Lichess Study question (game fragments)

Is it possible to input just a game fragment rather than a) a FEN and then manually inputting moves, or b) inputting the full game PGN and having to find/remember which move you want to start on? Those seem to be my two options.

If not, I would like to request this idea be implemented. Either allowing input of a (partial) PGN from a non-starting position or even allowing the deletion of moves /before/ a certain point rather than just after. Thanks!

You can input PGNs from non-starting positions. See the PGN specifications:

So if you have a whole game and want to input just a fragment from a certain point, you can find the correct move, add the two relevant PGN tags to the header, and delete the moves, keeping just the moves after the point you want.

You can't post in the forums yet. Play some games!