The grenade bug is many months old.
FTEQW supports both versions of BSP2 and probably has the grenade bug fixed... it's not Fitzquake though, if that bothers you.
http://www.fteqw.com/ftedownloads/experimental
note: with FTE, don't bother *not* downloading the "experimental" version.
You can force a netquake-like behaviour in FTE by setting / experimenting with these:
sv_nomsec 2
cl_nopred 1
You might have to set sv_bigcoords 1 as well to enable crazy map aka BSP2 support. Not sure if that's autodetected.
I'm pretty sure that at least DirectQ also supports BSP2. Not sure if QuakeForge, Proquake and Qrack actually implemented it yet, last I heard there was some interest though. I think QuakeForge might have it. That means several engines support it, actually.
Congrats on the release Tronyn! Keep making cool stuff.