Something I've noted in almost every game I've started since 2.2. In the phase where my empire starts expanding into colonies I've always suffered a crunch within my Empire's economy. I'm usually trying to buy and sell resources at a premium to make up for a critical shortage in consumer goods and/or energy and food (the later depending on the state of my colony's resource districts). Said glut, however, is quickly solved once the tier 2 consumer goods, alloys, and other buildings start coming online.
So it appears that to cover the massive resource requirements needed for a population growing across 2-3+ planets, you're expected to have those tier two facilities in production (or give up on unique planetary buildings such as the unity momument, robot fabricators, or hospitals on your capital). The problem is to efficiently upgrade to said buildings, you need 2-3 technologies (one for the building, and 1-2 for the resources themselves, depending on if you need to harvest, produce, or both). Which can take quite some time to get lucky with those rolls.
Considering this is such an early game crunch, perhaps the tier 2 production buildings shouldn't require strategic resources and instead said resources are required for the tier 3 or above midgame and later buildings?
Mmm, my experience is very different from yours. Or rather, my very first game abandoned after some 15 years of game time in 2.2 did start out with such a "now a glut of one thing, now another" - but that has not been an issue since then. My guess is that you have fallen into the specialist trap, something that has certainly been the case for many others writing about economic woes in 2.2, i.e. focusing too much on getting specialists to produce the "good stuff" before you've got an economy that can easily afford to field specialists.
If you use standard Decent Conditions as lifestyle, your specialists cost TWICE the consumer goods of workers, whereas if you've got access to Stratefied Economy from Autocratic you pay FIVE TIMES as many consumer goods per specialist as per worker.
In both cases you will greatly harm your economy by taking profitable workers that mostly require food, amenities, and a few consumer goods in order to produce resources and turning them into specialists that require more consumer goods and transform one type of resources into another.
Looking at saves from my most recent start as fast breeding fanatical spiritualist/authoritarian corporate dominion/cutthroat politics oligarchy in a large galaxy on Grand Admiral (later turned into aristocratic elite/cutthroat politics divine empire), the phases went like this:
2220-2209/2210: get 8 science ships out surveying (with Map the Stars), build temple, alloy foundry, and more districts on home planet. Nutritional Plentitude food policy, Encourage Planetary Growth as soon as possible. Gun for expansion traditions first and Interstellar Dominion as perk to allow more rapid expansion. Stratefied economy.
2210-2219: First wave of colonization consists of 5 colony ships - they are settled with 2 POPs each due to Expansion tradition, I resettle the extra POP from each of three of them on the fourth (the best) bringing it to 5, which allows me to build another temple. IIRC 3 of them were bought with energy (Corporate Dominion) and the other two normally. I have built a Civilian Industry site on the capital to produce the consumer goods necessary to support this extra population, but know that I'll soon need more - eventually every planet that reaches 10 POPs and stops being a colony will have both a temple and civilian industry to ensure amenities, consumer goods (and unity and soc research), but there's no rush. I want a rock solid worker economy before I start moving into specialists on a big scale.
2219-2225: I'm starting to feel the strain of expansion and need for the POP growth on my worlds to be resettled so I can produce more consumer goods, so I only colonize one additional planet during this period bringing me to 7 total including capital. The only one at 10+ is my capital, all others are colonies with the 50% growth penalty. But who cares? It is a lot more growth than I'd have by concentrating on only 2-3 planets at a time, and every planet that gets close to 10 start requiring significant investment over what is needed for the worker districts, so I would rather have many than few.
By 2225 I have 46 POPs of my own race, when I conquer a post-atomic indie civilization with 24 POPs that I enslave and start resettling on my colony planets (only 50 each for slaves).
"Twenty years later"
By 2245 I haven't conquered anybody else. In the interim I've only colonized two more planets and focused on building up the existing planets before starting colonization of phase 2 space that I have staked out by claiming many systems (and building two strategically important bastions in chokepoints, just in case). Phase 2 space consists of all the planets with 20% or worse habitability within my reach, as unfortunately I have no POPs with right climate, so I wanted a strong economy before their colonization. I still do not have T2 buildings, nor have I needed them to grow my ever expanding empire, which now consists of 10 thriving worlds with populations 39, 20, 2x16, 2x14, 13, 11, 10, 5. Some of these worlds
Empire size is 163 (51 districts, 46 systems, 10 colonies), total POPs are 158. Balance is +67 energy, +97 minerals, -27 food, +16 consumer goods, +36 alloys, +204 unity.
[-27 food due to having recently gone specialist on an agricultural planet, but I'm prepared for that with a 2.4k stockpile that will easily last until a few worker POPs have grown elsewhere]
So that was more anecdote than detailed prescription, but... I do think it is likely you are falling into the specialist trap and not focusing enough on getting a worker economy running. At least when I focus on the worker economy, it seems easy enough to go on an expansion spree.
I'll admit that this latest example is the best yet due to starting with Corporate Dominion and thus being able to pay for some of the colony ships with energy, which meant I didn't need as high consumer goods and alloy production as I otherwise would to have produced them - but on the other hand, one can also buy those resources for energy while using another civic than CD, so while this worked well, the advantage over not having CD may not be all that big anyhow.
