As a kid I used to have a few hobbies, computers, electronics, CB, engines & cars, shooting, home brew.. and I intermingled some of them such as passing through the quarry/tip when going shooting to see if any electronic stuff had been dumped that I might take home to fix or just take bits off for use in some project later. I made particular use of the BBC computer's analogue input and 'user port' digital output and had a mini solar panel (from a 300 in 1 kids electronics set) outside in a jam jar to meter light level and relay running off the user port to switch mains lighting in my bedroom. Then, noting that the channel selector on a CB just made various connections on the PLL chip, I replaced a CB channel selector knob with mini relays controlled by the BBC's user port output so I could use the computer to switch channels. With an analogue connection from the signal meter and another little program the computer could go through the channels looking for a strong signal, thus acting like a scanner.
Dad had ship to shore and CB radios on his boat and in his campervan (and car), before mobile phones you could make phone calls on STS radio but expensive. On one occasion we were parked on top of cliffs in Wales, made an expensive phone call to grandma and after the call Anglesey Radio queried the strong signal and their radio direction equipment pointing to the 'boat' being on land... illegal hehe.
Is this gas pickup at the rear or front end of the tank? Tank in spare wheel well or cylinder in boot etc? BRC installs usually have 4 hole tanks but in case tank is in wheel well it may have a 0degree single hole tank with valve pointing semi forward at 10/11 O'clock (because on that model the petrol tank has metal bracket protection that makes it difficult to fit valve through side of wheel well in other locations). Or may just be that change back to petrol pressure is set too high or reducer pressure set too low. The Jeep 4L is a low demand engine in terms of LPG conversion, spuds aren't in a great position but that might not be having the biggest negative impact. With some LPG systems it's necessary to 'advance the injection sequence' to prevent harsh gear changes and hesitation on acceleration, you can do that in software with some systems or can achieve the same by swapping gas injector plug connections.
Would maybe be a bit surprising if the BRC installer didn't just upload a standard map for the 4L Jeep.