I do wear a fair bit of foundation due to pores and uneven skin tone
It sounds as if you'll do better by preparing your skin for the foundation, rather than relying on it to fill pores and mask certain areas. Going back to your decorating analogy, you have to fill any pits in the wall and overcoat stains before applying a thin, even layer of paint. We'd better stop the analogy there, as you won't be sanding down or re-coating 😂
Try using colour-correcting creams and a pore-filling primer, plus a concealer if you still need one after correction. Let each layer settle before applying the next, and take a lighter hand with the foundation.
It's a bit worrying that you talk of your foundation drying out - it sounds as if you mean it's caking. You must be trowelling it on! After applying a thin, even layer of foundation, use a powder to help fix it. This again should be dusted lightly over your face. I use a loose, colourless, 'glowy' powder from Elf but, if you're still concerned about coverage, there are plenty of tinted powders. Put it on with a large, fluffy brush, barely touching your skin.
You can still use a setting spray after the powder if you want.
My skin flaked for two months after starting tretinoin, and still does it periodically. I found there was nothing to be done about it, apart from leaving off for a week. It is supposed to stimulate cell renewal. This means old cells must be pushed off, and it seems some of us have skin that clears them out in bursts (much like the way I empty all my rubbish the night before bin day!)