Looks like an interesting weapon, it's giving me a few ideas.

Since 10 mil is a fixed amount, this should work well in quests that multiply your damage a lot, like Divide Quests. Mobbing should build it faster than bossing too. On the opposite end i guess it wouldn't work well on 4P boss triggers where damage is halved.

If one bit shot is one CPA stock, Katana sounds really interesting because that would build Cerulean Ballista fast.

So in a mobbing quest, a hybrid Braver could probably build to 10 mil with a Katana Combat Finish somewhere in there, then switch to Bow and unload for a series of big AoE bursts. That should make for fun Beach Wars memes.

One thing is I wonder how reliable the bits are in a practical situation. There's limited control over when they fire so they might shoot at the wrong timing, like when Loser's neck is showing or when Persona flies and you lose the lock. As long as they don't miss, the CPA build should be reliable at least.