Whoa, it's a bit nerve-racking for me to read of people having trouble controlling the lens features. My whole set up, using the zoom method, depends on having reliable operation of the lens features. However, I'll be using a pretty sophisticated remote control set up - the RTI T3 and RP6 remote control processor.
The idea is to use the RS232 control of the JVC projector, into the RTI remote control processor. The RTI system learns the commands of the original remote control, then transforms them into an RF signal which is received by the remote control processor (which sits in your component rack). The learned commands are actually stored in the rack-mounted processor, which is physically connected to your device, so there's no fudge-factor of the commands going through the air and maybe not quite making it consistently to the projector.
Hopefully this will mean good control of the lens features via the RTI remote. Fingers crossed.
(Then again, I seem to remember when I was at Mr.littlejeans' house using his RS20 projector, that he had the lens features programmed into his Harmony remote control ok).