It really depends on what your trying to ‘debug’ I guess here.
Is it the query side of things, or DAX, or general report slowness…
Personally I’ve never really had to debug things that much because intuitively I can work out where things are playing up just by reviewing certain parts of the model.
For example, if the data loads slow it’s likely that there is just too much data, or too many columns, or data that can just be optimized way better.
If formulas are running slow, it is usually because there too many iterations occurring either the formula needs to be optimized or there is just too much data.
The way I approach things is I just follow my best practices for every development and I just don’t think you can go wrong.
Every chance I get a simplify, and this is across the entire report. Simplify, simplify, simplify.
Few tips here