Ya I have that too. Whenever I do cold showers or swim in the cold sea my floaters get way worse. I try to pinpoint for a long time what affects the floaters especially and finally noticed last days that it seems that the moment I get more consistent sleep my floaters get less intrusive. They get almost unbearable when I'm sleepdeprived even when I don't feel sleepy or tired.
And I think with hiit or so it made me a bit anxious/"weaker" already pre pfs(when I now think about it, backthen I never noticed shite xd). I belive the right balance is key. I think stressing the system is crucial for health and recovery, but giving enough rest is just as important.