Keeping a reference to a slot takes up very little memory, so little you should not worry about it. It is just a reference, not a copy.
Using Skeleton findSlot
likely won't make your app too slow, it is just a bit wasteful for the CPU to compare the names of many slots. Another option is to put all the slots in a hashmap (dictionary in C#) so you can quickly find one by name rather than maintaining many fields.