Btw, I don't understand the hate for 20-30 CL. Even 10-20 is bareable if you have enough autonomy reduction (forming a new nation, empire rank, monarchy reform, etc).
When the goal is to optimize expansion, you stay in the 20-30 or 10-20 range and constantly milk resources from estates. The subject thing is a meme -- it's an increase in LD from dev, which people confuse as just flat LD. It only becomes relevant if you have really large dev subjects.
I don't play past absolutism, but in the only run I have (the Ryukyu run), I found you only need to start thinking about revoking privs/consolidating estates around 1550s. Until then, I was always hovering in the 20-30 and sometimes dipping into high 10s range. Also, keep in mind dev pushing is a great way to farm crownland -- it gives 0.2. Even without the MP afk build, you can reliably get low dev costs later on in the game through prosperity/edict/burgher/university. Also be on the look out for -dev cost events, esp the -20% on monsoons.
So tl;dr?
- Use estates, don't ignore them. If you start as a minor, there is a case for only granting MP privileges without raising their influence really early on -- your first few conquests will spike up your CL massively.
- Hovering in 20-30 is normal. Even 10-20 for certain setups. Temporarily going into the 10s is totally fine even if you don't have the autonomy reduction
- If you're at 25 CL, sell and seize. The order is important -- you get more from selling at low CL, so it's better to sell at 25CL then seize instead of seizing and then selling at 30 CL.
- Abuse peace deal timings! If you're at 24 CL and about to conquer a bunch of land, sell first to get it to 14, send the peace deal (hopefully it shoots up past 15), and then seize.
- Consolidating estates can begin around mid 1500s. Use dev pushing aggressively to farm crownland