Amazon PPC Management Question

Question for those of you who manage your own PPC (or outsource to agency or VA):
For a brand with existing campaigns:
1 – how much time per week do you think is necessary, on average, to check-in, optimize, and manage the PPC on an account.
2 – how frequently do you “touch” your campaigns
I’ve got some VAs doing this, and I’m puzzled sometimes that they are putting 1-2+ hours PER DAY (according to screenshots in Upwork) inside Perpetua (our campaign management platform) looking at PPC data. I just feel that’s excessive, but dont’ want to micromanage. Thoughts?