I'm bit too busy/tired/lazy to go through AO sources but those SCSP changes might affect AICA as well.

First, there is an undocumented bit (Neill calls it "voff") that does the same as SDIR. That is: LP, AEG and ALFO will not affect channel volume - but everything still gets computed. That means no matter if voff is on, if AEG goes (or is set) past ATTACK and the counter reaches 960 it will cause the channel to stop.
That is bit 6 of register 0x28. Incidentally bit 5 in that register will turn off lowpass filter (aka all-pass, again it is still being computed anyway).

Now, this is for amplitude side of things. I don't know if "voff" affects PLFO as well - right now I assume it doesn't but I guess this should be verified one of these days...
PLFO (the resulting frequency shift) is somewhat tricky anyway.

Second, Neill was very specific in his explanation of LFORE:
If set, the LFO phase is reset at the start of EACH SAMPLE LOOP.
And so this is exactly what I'm doing. I assume the big letters mean he checked it himself and is sure of it, so I didn't bother doing it myself.
This is how AICA does it and since the FQ8005 doc doesn't say it was changed, I'm willing to bet that SCSP operates in the same manner.