Hi,
Thanks for the pull request! While we understand the needs around derived plugin classes, unfortunately its unlikely we can take the request as-is at the time of writing. This is due to a pending refactor that will realign the data access patterns of USkeletalMeshComponent (and USkinnedMeshComponent) quite significantly, mostly around threaded access to buffer-like structures that are processed per-tick. Making the various inner data structures effectively public API would complicate this undertaking so we would prefer to defer it to a later time. If however your needs are restricted to ‘settings-like’ members, e.g. internal flags that are not updated per-frame etc., then we could consider accepting a PR with a more piecemeal approach.