It's pretty unlikely that anyone with years of salsa (or other partner dancing) experience would go through beginner's hell if learning another dance.
To offer my own experience with kizomba: I had very little experience with it, 3-4 months of weekly classes but very little social dancing (this was before covid). Those courses gave me a good technical foundation with basic kizomba dancing, but not much more. However, I also had my salsa (and ballroom, and bachata) 10 years' experience to help me.
Fast forward to June of this year (having not danced any kiz since my courses in 2019): I show up in Paris and get into the kizomba scene intensively. Within a few weeks, my dancing shoots up to a level where I can now follow super-intricate leading, in all kinds of styles, from some of the best leads in Paris, who tell me that my following is at an extremely high level, e.g. that I can follow subtle weight transfer lead cues that most kiz follows can't.
Another way to gauge how good you are as a follow in kizomba is how long the really good leads dance with you (because in kizomba you can dance anywhere from a couple songs, if the compatibility is not great, to...tons of songs with the same partner if you have good connection ) -- back in June, the really good leads would dance with me for a few songs on average, i.e., not that long. Now, I have some of the best leads in Paris dancing with me for an hour+ (my record so far is two and a half hours with the same partner

)
(This is no small feat in a scene where the lead:follow ratio is often 1:2 or higher - meaning, there are a ton of follows competing for good leads.)
Dancers who have been dancing kizomba for many years, some 10+ years, will ask me how long I've been dancing it and are shocked when I say, just a few months -- they assume I have years of kizomba experience
So, all this to say, I successfully avoided beginner's hell completely thanks to my prior dance experience. Fairly certain I would have had a very different experience had I started kizomba with no dance experience.
All this to say, if fear of beginner's hell is a factor in not wanting to learn another dance, I think one can rest assured the beginner phase will be a lot smoother than with one's first partner dance.