Why wouldn’t you use that maintainer at competition? That’s what we have and it works gloriously.
If you are using batteries faster than that something else is wrong with your competition set up. We use #1-8 our first day, then use the #9-10 the second day before rotating back to #1 and #2. By eliminations we have all 10 batteries topped off again and ready for action.
We haven’t charged a battery over 2 amps in years, and use batteries for 2-3 years before demoting them. We also keep 2-4 old practice batteries for non-match situations.