I return with news.
After cleaning up the redundant code, my graph now looks like this:
I don’t understand why but it seems that the jittering is gone. It returns if I remove the IsLocallyControlled branch. I also don’t understand why a check of local control on the authority should affect the jittering of the remote.
Replication works with the above setup. Sometimes tidying your code fixes problems one couldn’t solve before.
I have a new problem however. It would seem that my rotation is not frame rate independent and I don’t know how to make that so. As you can see, I’ve clamped the value of VertSpeed in an attempt to stop the character from over-rotating on slower clients but this leaves me with the slower clients rotating more suddenly than I’d like. You can see the current state of the rotation in this video where the server is on the left and client is on the right:
I think the source of the problem lies in the function I use to set VertSpeed here:
As you can see, if a computer has a slower frame rate, more time will pass between ticks, and thus a larger number will be read into the Target pin of FInterpTo. Alas, I don’t know how to normalize this value. It seems this questioner HERE had the same issue though.
Thanks again for your time. All advice is appreciated.