Hey folks, hoping to find some suggestions of where to look next on this. Here's the situation:

90 CRX Si, 190kmi, all stock expect a mini me swap done by the previous owner, which consists of a Y8 head, P28 ECU and obd1 distributor with a wiring harness conversion. That was all done probably 10 years ago and hasn't been any issue afaik.
A few months back the car started randomly stalling or nearly stalling any time the brakes were applied, often accompanied by a flashing CEL. The degree to which it does this varies, but pretty much cannot be driven any distance as eventually it will die. I initially assumed it was a vacuum, MC, or booster issue, but it turns out it's actually electrical and is triggered by the brake light switch. The switch itself appears to be fine as removing the connector and shorting the two terminals results in the same issue. The brake lights all function normally, and no other electrical load causes this to happen. It's charging at 14V and everything in the car works as it should.

About a year ago, the car did have a problem with an overcharging alternator (Autozone crap) that started putting out ~16v and fried the coil, but was driven several hundred miles after I fixed it with no major issues apart from the common, annoying idle surge (I've tried cleaning the IAC and replacing it with a chinesium eBay one, but still the same) Idles beautifully on cold start though.....as long as you don't touch the brakes.

Any ideas?