Standard YC SAFE is for corporations (C Coprs), not for LLCs, as LLCs don't have shares to convert to, only membership units.

While there are SAFEs for LLCs, I don't get their purpose.

Maybe they can be useful for bootsrapping Micro-SaaS or lifestyle businesses.

https://jmdorsey.com/safe-for-llcs/

https://mccarthylg.com/can-an-llc-use-a-safe/

I guess:

A gets $60000 which is 10% due to cap.

B is below cap so gets $50k worth of shares in the pile of cash. Or $50k if you like.

Check the terms: it becomes debit or prorated shares