Good news, Neal! This has been implemented and will be available in the next update.
this is now available in the latest Royal TSX V4 beta (V220.127.116.11).
You can get the beta here: https://www.royalapplications.com/go/kb-ts-mac-downloadbeta
Please let me know if the feature works as expected!
This has now been rolled out in Royal TSX 4.1.
When using control-tab and you are on the last tab, control-tab does nothing. I have to select control-shift-tab to go backward in the list. I WISH greatly that control-tab would cycle to the first tab in the list of tabs when pressed while on the last tab in your list. This will help with my efficiency for sure. Please allow :). Thank you.