CTRL and Alt/Option Keys on Touchbar over Thinlinc

Hello, I’ve downloaded the Trial of BetterTouchTool and I’m looking for help on using BetterTouchTool Touchbar buttons over Thinlinc.

I’m using my MacBook Pro to access my Linux workstation via Thinlinc, and I was able to use BetterTouchTool to create Touchbar hotkey buttons that work through Thinlinc that run on my Linux, however the CTRL and ALT buttons don’t seem to carry through.

For the Mac to Linux keyboard keys, here’s a description of how Thinlinc remaps the Alt and Command keys. From Thinlinc’s admin guide:

8.2.4. Command and Alt Keys on macOS

The Alt key (also know as the Option key) behaves very differently on macOS compared to its behaviour on other platforms. It closely resembles the PC AltGr key, found on international keyboards. ThinLinc therefore treats these keys in a special manner on macOS in order to provide a good integration between the client and the remote ThinLinc system.

Whenever either of the Alt keys are pressed, ThinLinc will behave as if AltGr was pressed. The left Command key is used as a replacement for Alt in order to use shortcuts like Alt+F. The right Command key retains its behaviour of acting like the Super/Windows key.

https://www.cendio.com/resources/docs/adminguide.pdf

Because the MacBook’s Touchbar Buttons generate Mac keystrokes, I was hoping that those would still carry over though ThinLinc, but that doesn’t seem to be the case. Any thoughts or advice would be appreciated.

I’m using a 2019 16-inch MacBook Pro, running Catalina.

I saw another issue that sounds similar to the issue I'm having: