By your idea, all stars in Stellaris are perfectly matched to thier realworld sizes.
G Class Star "Sol" in game:
B Class Star.
2-16 times Sol Mass. 2.7 -10 times sol Radius.
M Class star/Red Dwarf.
0.075-0.50 Solar Masses. 8-62% of Sol Radius.
They are pretty much the same size.
Despite one having between 8 and 62% of Sol's Raduis.
And the other having 2-16 times Sol Radius.
And since we talk about a 3D body, changes in Radius would literally scale cubically (that is one step up from Exponentially).
And even less true for modding - which my question aimed at.
And sine the patch is not yet out - much less the scaling mod that will be made for 1.5 - you were asking for a educated guess.
Wich is what I gave you. Wich was: "Propably not".
We have no idea if we can dynamically set the yield of a dyson sphere, based on what star it is around. I would not bet for it.
There is a chance the Dyson Sphere will already scale to G, B and M class stars. If so, even a "realistically scaled" 100-times Sol Radius Star would be properly covered. It would propably take up the whole System view, but it would be covered.
If that does not happen you have to work with Scaling of Models. The same things the Oversized ship model does. At wich point we would be back at "can we figure out the star size?" question.