Yes it is.
Usually eyelashes are part of the base mesh. Not a separate component and not a separate groom.
you can always just grow them via material shader wile retaining all movement if you need to allow for customization.
at a base level, you are also probably better off with a single card per eye and a transparent material.
Otherwise you can’t really control how many lashes are present without changing mesh - and Making it modular you not only waste resources at runtime, but you also run into creation issues like the one you are having with morphs.
If you absolutely don’t care about issues.
/performance, and/or you need a cinematic,
Then just don’t use groom.
Go with a finished mesh that is just swapped at runtime and has the same blendshape as the eye.
The benefit of that is that you can cast raytraced accurate shadows from the lashes. Which at that point should probably be modeled as a an hexagon with 2 to 4 thinng sections coming to a point and shaded smooth.
eyelashes refract light differently than hair btw. Particularly when they have mascara on