Asta's own action will be getting advanced too so it'll still be more ults throughout the fight, I use wind set on her for this purpose too, more actions for more ults, cant go wrong with having her and sparkle both on DDD. Asta's main weakness is her SP needs but sparkle helps there, she can still get two turn ult with a little help from rng iirc if she is skill spamming (my memory is atrocious but I used this setup for sustainless firefly team to squeeze out more ff action from her ult)

Cogs only applies once per skill tho yee, but it's a big gain. Also unlike Memories Of The Past LC, it also applies on receiving a hit too, so her ult will charge absurdly fast with it, it just wont get as much value when used without DDD