In reply to David Anderson.

This isn’t a question of just UI choices. This is a question of misleading description of what that function does. No other optimisation tool I’ve ever used has had “Defer JavaScript” as a “testing tool to bypass page score tests”. Deferring JavaScript servers a different purpose (legit optimisation) and the fact that, only in a related setting you have a small text about this is a dark pattern. Intentional or not.

It would be much better for you to recognise these following things:
1) The text should be on both of the options
2) It should be called something more descriptive than “defer JavaScript” to avoid people mistaking it for legit optimisation

Now these things are not a huge deal IMO, it could be a simple mistake or not thought out completely. However the practical effect of this now is that, even a semi experienced developer like me, could very easily miss this and just try to optimize my pages by deferring all JS. If I didn’t read the fine print in the other setting (and understand it also applies to the other since it’s far from clear) I’d feel cheated.
I’m a bit surprised you’re not ready to budge on this – it makes this whole thing feel like you’re hiding something and that this is actually intentional. If you said “Yeah, I can see why those settings can be misleading and we’ll look into fixing it to be more clear” this wouldn’t be an issue, for me at least.