I currently have no plans to support the Devo7.

Yes, the "Devo7" is generally a red-headed step-child, but it works, despite its minimalistic interface.
Its MCU the STM32F100C8T6B which lacks built-in USB-support like the MCU in the DEVO10 and 8, but has USB support thru that other gizmo, and the RF module is the same as its better siblings.

With a web-app, like rc.fdr.hu/model.php a fancy transmitter GUI with touchy screen, is a moot point. Visualization on a lap-top or tablet, even at the field, should be superior.

Would it be difficult and time-consuming to adapt the code to fit this version of the MCU?

i also hope someday Devo 7 supported protocol , although display not optimal, but
it work very stable and cheap .

The lack of USB support is not an issue. The main issue is the fact that it has half the flash space (64kb instead of 128) and less than half the RAM (8kb instead of 20kb). Even the 7E with 128kb flash has to cut out features already because that's not enough flash. Not to mention that the chipset in the 7 runs only at 24 mhz, while the 7E runs at 72mhz.

I imagined the better display was the reason the larger memory and faster processor. Multi-protocol may be bitchy with that simplistic display.

Has anyone made an RF-switch for the multi-RF module setup? Only one protocol at a time, thus a single RF-signal is used? A single antenna should be OK as the same frequency is used (2.4GHz) for all of them?

Has anyone tried to use a ceramic patch antenna (RHCP) for the 2.4GHz TX?

The metal handle looks well insulated and could possibly also be used as an antenna, with a tuning circuit of course, for whatever frequency used.

Thanks FDR !