Question Info on methamphetamine separation during the boiling process?

[Power]

All I was told EEF meth is 95% active methamphetamine and it’s counterpart whatever it’s called is only 15%

I’ve read before that they are supposed to keep doing something during the cook to purify it but don’t and just leave the two together for a bigger yield

if anyone knows what I’m talking about here can you please explain it better