Models which use inverted profiles on the horizontal are typically the "lifter" type, which have no need to fly inverted, although when empty they can be forced upside down.
If inverted flight is part of the flight requirement, then a conventional symmetrical horizontal should be used.
Worrying about flaps while inverted.. Why?
Or spoilers?
It's wasting resources to be concerned about transient situations which may never occur.
Don't overanalyze this situation, go and build and fly.
It's much more productive.