Looking for more pep off the line

Hence the need to measure the timing vs rpm.

I hear ya though. Skipping that step and going blind into 4000 rpm plus at full load would be super risky.

Let's bring this back to a strategy that I would recommend for this situation.
Limiting the advance shouldn't be needed because 3000+ rpm tuning should be put aside until the foundation is put on solid footing. That said, we know some people just can't resist their urge to floor it.... so this assumes Alecb, you have the patience and interest in solving first problems first.

First problems here are:
a. Some fault in charging system (that can be worked on with the current tune just as it is)

b. Idle and off-idle needs performance tuning and testing. (that can be worked on with the distributor as it is as long as that includes timing vs rpm measurements. Without those, then after making internal changes to the distributor you will be starting from scratch). You can drive it on the local streets, but avoid flooring it or high speed stuff.