Finally have access to a computer able to run BP smoothly (and the time to play it all the way through), and I'm coming up with a couple annoyances. Neither encountered so far is a game-breaker, and one I found a somewhat-unsatisfactory fix for that does work.
1) Double-HUD. I know this is a very much known bug, but it's annoying not being able to play on native resolution and have to set a launcher flag to fix it.
2) Weapon projectile bitmaps have been going crazy for me. Initially I tried playing the retail campaign with BP2 as the active mod (I've done it before, so I know it can be done without any previous visible harm). When I played the training mission to make sure all my controls were working right, I discovered that every time I fired my primaries, the left Subach bolt would display correctly, but the right would simply be a ball of white. No detail, just a big ball (relatively, much larger than the normal projectile) of light, which still produced lighting effects. Retrying on an AoA mission with the Prom S and Balor confirmed the issue on this computer. Just in case, I checked with WiH, and the issue is there too, affecting the Vulcan I tested it on.
The general behavior seems to be replacing every other or every third (or sometimes more frequent) projectile with the aforementioned white ball. In several instances, the projectile fired correctly, and reverted to the white ball mid-flight.