I suppose the most immediate method for hiding a variant without deleting them would be to add a class (in bootstrap 5 it would be .d-none) to the specific option in the options area above the variant.  This would start to get tricky if you are using that option for multiple variants such as size and color.  I will look into possibly adding a field at the variant level for a custom class that would give you that option, however the downside is that if you are using any modified template file to display those variants, that would need to be updated on your end as well (which we can provide the instructions on how to do that if that is the route we go - it may be a simpler option, but I am adding it to the future features list.

Adam