In gear or park/neutral?
I had bushpig f280 in sle idled 12oo'ish neutral/park then 1000'ish in gear according to rev tacho...any lower it would want to stall unless it was operating temp although big ol stally helped it heaps untill touched brakes.
vp ute has some crossbred 268/276 cam idles around 900-1000 neutral/park & probably 700- 800'ish according to archaic vp rev tacho...does want to push on stock stally.
I wouldn't worry as long as it's running smooth & doesn't stall or push on convertor when in gear...with new setups they'll change as you find & fix or change things untill it's all sorted outed & reliable.
When car is finished later on down track data log it running/driving send back data they can then touch up the memcal tune.