I decided to go ahead an install the ASIO4All for the Kemper. I was worried about having two ASIO installed and causing conflicts but no conflicts occur. I can just easily select from Reaper Preferences options to select either the Motu or 4All driver and it's corresponding inputs and outputs. BTW, my Motu has lower latency 3.2ms at 128 buffer at 48k. The Kemper has 3.6ms at 160 buffer at 44.1k.
Now that the drivers are loaded for the Kemper, I will play some youtube videos and select different playback configurations, including having the Motu interface ON while playing thru Kemper, and see if the problem can be duplicated.
I will report back later.