I just finished a chat with Samsung regarding the ability to have both front and rear cameras operating at the same time for the Note 10 Plus. I was told my concern would be going to the update team and I was given a support ticket so that I would stay notified about the progress but it seemed fairly certain that they would bring this feature back soon in a phone firmware update. I would suggest to anyone that wants this on their particular phone that they contact support and let them know. I will update this thread as I hear of progress.
That would be awesome! I really miss that feature & used it rather frequently on my S6 and Note8. I had an APK that allowed it to work in my Note 8, but since the update it no longer works. I hope they bring it back.