safari specific short key redirection with Ü and [ results in infinite loop

Try to redirect the "command shift Ü" to "command shift [", so that I can switch tabs within safari with the same keys for both US and DE keyboard layout.
The shortcut should trigger the other shortcut, but instead, the last sequence I type in overwrites the other (input, trigger, and vice versa), so I end up with a loop, that either
command shift [ triggers c.s.[, or c.s.Ü triggers c.s.Ü.
This leads to infinite loops, that make BTT crash ...

BTT always records the physical location of a key, not the character it produces under a specific layout.
Because of this it will cause an infinite loop.

I should add some code to prevent these loops though and just show an error message.