I was looking into it to see if I could use it for solo mining, I believe it is on par as a node, and as you point out probably better and continued support seems inevitable, but if I recall correctly I was looking at just a development road map and it didn't seem like there was demand to support the mining functionality, going forward I felt it wasn't worth risking if a block didn't propagate so I am not sure it will be used for mining.
Ah. Thanks for your clarifications. Mining support has been implemented for quite some time now. I'd have to check the commit logs to be certain, but I want to say that mining support went in around the end of June, 4 to 5 months ago. There is nothing on the development road map for it because there isn't anything else to do for it currently since it's complete.
It's a fairly simple matter to find out if a block will propagate by using BIP0023 block proposals since it checks if a block is valid (excepting the proof of work), before you ever start working on finding the nonce. In fact, if mining infrastructures started to migrate to checking consensus against multiple implementations in general (or even multiple versions of Bitcoin Core itself), it would be beneficial to the miners and the entire ecosystem in the long run since even accidental forks between Bitcoin Core versions (as has already happened in the past) could be detected and handled gracefully.