On the capacity loss issue, wouldn't changing the cap tube out for a TXV help alleviate some of that? This is the one I was looking at.
https://surpluscityliquidators.com/p...-txv-hp80.html
Externally equalized but it's flare fittings so maybe less chance of burning it up.
Another option:
https://surpluscityliquidators.com/p...weat-r134.html
Internally equalized so one less joint, but brazing a heat sensitive component is risky. Going to practice brazing before I work on the system but I'll still be pretty green.