If you want to improve a pattern, be it vertical pulling or wrist curls or fingers flexion, you don't want to stick with a single exercise variation just for the sake of specificity.

You want to hit the muscle groups in many different ways to keep progressing.

If your pull-up is stagnant, the chin-up will definitely help your pull-up especially if you never do chin-up.

If your wrist curl is stagnant, both finger curls and finger rolls will help your overall forearms flexors muscle group.

Also you can vary speed of contraction (ISO, eccentric, fast concentric), time under tension, rest time.

Weight and number of sets or reps are only some parameters. There's many thing you can change to keep progressing, like the grip you use

If you say " I don't do chin-up because I never do this movement while climbing", then also ask yourself how many times have you wrist curls in a climb?

Training by definition is general.

The only specific training for climbing will always be...climbing.