See this Comm Center message by Dick Berg, and the ones following. Currently the Catalog Maximum Magnitude in AcquireScheduler is fixed at 18. Same problem in AcquireImages for ACP.
The solution is to put a common function into AcquireSupport which returns the catalog maximum. It would determine if ATLAS is in use, then which mag bands are present (down to 20) and return the max mag for which catalog bands are present. No user setting needed, and simply adding another band will extend its coverage.
