I would not increase light intensity. I would actually lower it or shorten your photoperiod. For the gigs that I've treated, they seem to inflate during the day, then at the same time every day, begin to deflate. I think there is a direct correlation with the zoox getting too much light -- essentially they reach their maximum capacity -- then the gig deflates. When I say "too much" I mean capacity and not intensity.
I've kept another batch of gigs in a tank that was never brightly lit, and one gig never needed treatment, while the other partially deflated. I'm treating that one just in case.
Your gig does not look that bad, and if you haven't changed antibiotics already, you may consider continuing your current protocol. Partially deflated is completely different than fully deflated, where it looks almost dead and lifeless. If it was ever fully deflated, then I would consider changing antibiotics. Of the four I currently have, two are now in the DT (one was in Septra treatment while the other never needed treatment).