There are many different ways of brewing gear and almost all products can be made not to crash but some just don’t cooperate well such as base compounds, 1testcyp, and inj oral compounds.
I won’t use products that crash because im lazy and don’t want to have to bring back the product every time I need to inj but also because some can be made at lower doses and they will hold. Its also true that heating a compound over and over can damage its potency if not done properly. I wish I could explain that part better but its a chemistry thing and ive never brewed my own gear so I can’t really give you solid facts. I know someone who can but im not sure if he will come out and comment on this topic.