It's so easy to get carried away with all voicecounts, pannings, and choruses and forget that the JP8 was 16 VCO, 8 voice, upper/lower hard panned L/R, and didn't have chorus. Not sure what trims were available on the PCB, but the "calibration" section is also not open for adjustment of the average user back in 1981.
By forcing the true Synthesizer mode, you have to make patches use the voicecount in another way.
On a sidenote I just tried the Arturia version, and....pwhaahahaha
Just don't. It really sucks.