I would agree with everybody else.
If you're going to do an integrated course, then obviously you go straight into ATPLs without the prior PPL knowledge. However, if you're doing a PPL, that would assume you are doing a modular course (despite some people doing a PPL prior to doing an integrated course for experience).
The level of understanding for an ATPL is quite significant to that for a PPL. It's like doing a degree before your GSCEs. There's no point, you'll confuse yourself, especially if you're self studying. It'll also take you 5 times longer.
For PPLs, you need to know what things are called, what they do & why.
For ATPLs you need to understand the above x 3 plus HOW they work in detail.
Walk before you can run