It's a minor thing IMHO because provided the aircraft is loaded correctly you can safely get airborne regardless of the trim setting (well, presumably within the range of not triggering a config warning).
It's true at least for A320. For all old MSNs the entry of Stab setting into the PERF page was nothing more than a scratch pad entry. If you entered rightly, wrongly or didn't enter at all never triggered any warning. But correct aircraft loading is always important. Long ago there was a discussion here in which wrongly loaded A320 the nose came up as the thrust was set and could not be brought down till Thrust was reduced.