> Is possible modify the A-187-1 in order to have a trigger or a
> gate input for control the bypass momentary switch

If you are familiar with electronics you may add a transistor that bypasses
the manual momentary switch (it shorts to GND). Another solutions is the
usage of a VC switch (A-150) and connect it in parallel to the existing
momentary button of the A-187-1 board. I have to point out that such mods
have to be carried out by qualified personnel only and that warranty is
void.

Best wishes
Dieter Doepfer