No experience with whales but used the same setup for sailfish.
Here is the best of that trip.
2 others on the trip had massive domes on FX housings. While their resolution was probably better, they were definitely envious of my far smaller setup and talked about it. They used a cord to tie the setup to their wrist so they could not drop it. I added that after the first day as well.
If I had it to do over, I would stick to the mini-dome and 10-17. I used no flotation and did not feel the need for it, other than the risk of losing it.
One suggestion, I wish I had done more cardio training in advance. I did plenty of fin laps in a pool in advance and never had muscle problems but thought my heart was going to pound out of my chest from trying to keep pace then stop the bait ball. No idea how needed that is for whale work. Just a thought.