Flowers appear on new wood. You probably would not have significant new-wood growth in this flowering season. With that in mind, it’s probably fine is you neaten the plant by trimming it now. As noted, this is considered an invasive plant; if invasives could be eliminated by simply pruning them out of season, more people would do that. (no judgement call here; just explaining from a different perspective)
Flowers appear on new wood. You probably would not have significant new-wood growth in this flowering season. With that in mind, it’s probably fine is you neaten the plant by trimming it now. As noted, this is considered an invasive plant; if invasives could be eliminated by simply pruning them out of season, more people would do that. (no judgement call here; just explaining from a different perspective)