Low FPS or 1000ms debounce times

Actually, as stated under rule 1.3 modifying your debounce time is not allowed on cubecraft and will result in a punishment.

For your question (assuming your'e a bedrock player), I think 20fps would overall be much easier than limiting your hits. Although I wouldn't call playing on 20 fps an enjoyable experience, you can get used to it, and im sure you can get quite good with it.
I know some people who play on very low fps (20-60) and still manage to beat me and other players consistently.
On the other hand, 1000ms debounce time would give you an enormous disadvantage which I doubt you'll be able to overcome. And again, it's not allowed :p

If you were talking about java 1000ms wouldn't be much of a problem due to the existing 1.9 combat hit delay.

Edit:
P.s. I'm not a bedrock player so my knowledge on bedrock pvp is quite limited, please correct me if I've gotten anything wrong :)

I'm genuinely concerned as to how 1000ms debounce would work