Improving Single Point LPG mileage?

[320touring]

I've finally started to get fairly steady LPG tanks out my 328i, now I'm looking to improve the efficiency of tthe LPG components..

Car will be getting serviced shortly- would changing the spark plug gapping have an effect on the following:
1. Ease of starting on LPG (i'm loth to use Petrol if it can be avoided0
2. Performance/volume of fuel required for a given load(i.e. more complete combustion)

The car has a single point system that feeds into the air intake, rather than injection into the manifold.

Car is fitted with a MAF- so not apparently affexted by a Warm AIr Intake when running on epetrol, but I'm wondering if hotter air may improve vapourisiation for LPG?

any other hints/tips/observations would be gratefully recieved!

Thanks