I looked and found another utility that boots multiple iso's and also provides persistence. I used MultiBootUSB to install three isos of which I've only had the time to verify two, 16.04 and 18.04.3. The 19.10 iso wasn't recognized as a ubuntu iso (probably because of its size) and did not offer the ability for persistence. I installed a wireless driver, changed the panel interface and the desktop background for each and it saved my changes.
and a download page:
http://multibootusb.org/page_download/
where I downloaded and installed
python3-multibootusb_9.2.0-1_all.deb
Its worth a shot DLS.
Edit: A couple of days later after going down several rabbit holes experimenting with different methods of getting 19.10 to work on the multiple USB, I'm done. I have a persistent live USB of UM 19.10 which works superbly and I will leave it at that. See my previous post on Unetbootin -