Don't do anything
The first was closed because it doesn't come anywhere near close enough to the standards we require on a question's scope. It asks 4 questions at once, and answers could literally be anything that might constitute golfing advice. In particular,
Do you have any suggestions for this language?
and
What features do you find useful?
are blatantly not part of a question we allow here, as they're entirely subjective.
The second one is a much better version of this question. It's still rather broad, and it overlaps somewhat with this question about community engagement. However, it asks for tips in designing a language to be good at code golf, as well as tips for actually implementing that. Additionally, it mainly asks for advice around generally creating a language, rather than specific features that would do well in a golfing language, meaning that this precedent doesn't apply here.
It's not too unusual for older, lower quality questions to be re-asked as an improved challenge. This is yet another example, just as a tips question, rather than a challenge.
I don't have anything against closing the older one as a dupe, but given that it's low visibility, already closed and inactive, what's the point?