Rubber Base or Builder Gel to Improve Nail Health and Strength?

I have weak, thin and bendy nails from doing gel x a bunch. And I’ve been told recently that rubber base is a good option and I’ve been looking into it. However, I’m not entirely sure about the differences between that and builder gel? They sound like they do the same thing. Can somebody give me more insight to this?

And if rubber base is something that will help strengthen my natural nails, what brand rubber base should I buy?

I’d also like to know the steps to then do my gel x, can I apply the extensions on top of rubber gel and while changing sets, can I leave the rubber gel on and do a quick backfill?

Thank you!