Chessply.com training's tool has potential, but it lacks the input of variations ... so you can only train the one line you selected. It's still in beta though.
This buggy feature was one of my main reasons for returning to Lichess. The regular trainer has seemed rather buggy lately, but I still love it.
I'm very disappointed the opening trainer is gone. I'd gladly sign a waver or whatever and play it, bugs and all.
Does anyone who builds lichess know how easy it would be to resurrect a local copy of this deprecated treasure?
Add me to the list of people who used and liked the opening trainer.