Hi Giovanni — I think it will be hard to continue too long with the 3/7 and only body weight exercises. You can do some creative things like with pushups, putting your feet up so you are tilting down more adds about 9% increase in difficulty, hands together vs shoulder width increases the difficulty, etc.

But ultimately your strength will begin to exceed the resistance without being able to add in weights imo.

As you note, focusing on the pyramid itself and low rest will definitely have an effect for the short term, but longer term I expect you’ll have to add weights in some way to continue the progress.

Hope that helps!