I have spent quite some time to have the chess engine plays vs itself with all the variants. Then I have saved the games and reloaded them in review mode.
While I didn't fix some minor issues, most of the crashes have been fixed.
The tactics have been disabled for several variants, specially Crazyhouse, for performance issues.
The chess engines console is back!
As in the Unity version, you need to press F6 to toggle it.
There is a known display issue when reviewing, the board can appear wrong (but the internal positions are correct). Pressing a combination of F2 and F3 will restore the correct display until a fix is made.