How compatible are 2014 third-party subclasses with the 2024 Player's Handbook?

Hey folks,
I’ve been digging into the 2024 Player’s Handbook and saw this line under subclass rules:

As I understand it, this means that older (2014-era) subclasses should still work in 2024 games, you just gain their features when you reach the appropriate levels.

So here’s my question:
Has anyone run into any actual problems when using third-party subclasses made for 2014 D&D in the 2024 rules? I have Subclasses Revivified but it is for old official subclasses. there are still tons of thirth party subclasses I bought.

I usually allow some well-balanced third-party subclasses in my 2014 campaigns, and I’m planning to keep them in 2024 games too — unless there’s a good reason not to.

Have you had any mechanical or balance issues with 2014 3rd-party subclasses in the new ruleset?