This request brings up an interesting point.
Given there are 100s of cryptocurrencies, Whonix should probably make a point of only officially supporting the top players with specific documentation e.g. Bitcoin and other large players.
Then, when users continue to come to the forums in the future with a support request for the latest fanboiscoin (#56/542 available at that time), it can be stated that it is not officially supported i.e. the Free Support Principle applies.
probably a good idea. though, i’d suggest considering that approach for all cryptocurrency. that’s more personal though. wall streeters are now treating cryptocurrencies like penny stocks. a lot of the hype around various cryptocurrencies, if not all of them, appears to be driven by finance bros who know nothing more about a currency other than that it is being hyped by finance bros. there appears to be no shortage of coders looking to take advantage. scamboiscoin? 
From Anonymous Money we link to separate pages for:
For everything else we can say unsupported.
But I woulnd’t mind users talking to each other without Whonix team investigating much. For example monero in Whonix with torsocks for better stream isolation doesn’t have much support from Whonix team.
I don’t think I’d use any time for fanboiscoin or similar. I’d even not be interested to look much into Ethereum and Ledger Hardware Wallet at the moment either. But the current docs can stay as is in hope it’s useful to someone and in hope someone will improve them.
Mist - Ethereum integration Whonix 14 - #3 got the suggestion to sort it out as per free support principle. The related wiki page Ethereum - Whonix is already known by the user and it says unfinished in bold, capital letters. That page tells how to do it in principle but since tunneling UDP over Tor is required admittingly only advanced users can achieve it. So while that page is a stub it can be useful for advanced users.
In summary I am not seeing much of an issue currently and it looks to me that mostly/fully(?) your suggested policy is in place already.