"e.g., the Teves (or ATE) Mk 4."
I have one at home from a 35i model; it has a wire connected to the brake light switch.
Unfortunately, I cannot say whether the ABS system interprets the action as "brake being applied."
My personal experience so far has been that when a circuit breaker is tripped, an error is logged, either during the tripping process or shortly thereafter. Consequently, there may also be various errors logged in other systems, especially if they are networked.
Now, let's get to the main point: intermittent errors sometimes disappear after a certain amount of time, and this may also apply to these specific errors. In at least one case, the warning light went out again; although errors were still stored, they were only saved for troubleshooting purposes and did not affect the ABS operation.
So, as always: Nothing is mandatory, everything is possible.
Okay, I've also noticed that it's not a constant error. But now, the crucial question again: Where would be the best place to install a switch, or rather, to insert a switch, to turn off the ABS?