Crank, your reinforcemnt is also a kind of modification, and on that weak place it sounds oké of cours. Especially to compensate the engine weight.

About the switch, I did show this picture in the past.

The switch detects g forces of moment of touch down. A second (back up) switch is mounted on one of the main legs of the landing gear.

On my transmitter I can select normal manual throttle control but also cruise control, an electronic device to give the Taurus more constant speed than constant speed by drag.
In fact one more step Ed Kazmirski could not make in the past!

When fly the Taurus with cruise control, the measured airspeed is maintained within a very narrow band of a few km/h, m/h. The controller manipulate the throttle servo for me. I only make the choice of the wanted airspeed. For example 50 % throttle stick position really is 75 km/h , 47 mph.

A third selection I can make is ; cruise control and switch over to normal manual throttle control on moment of touch down.

With this selection I land the Taurus, the cruise control does prevent any stall during flight and especially on final, the touchdown detection does switch over the cruise control to manual throttle control.
When the controller is not switched off it will speed up the revs of the engine to maintain the airspeed on ground level. Even in the strongest wind the wind speed on ground level is nearly 0 km/h (especially on grass) so the plane will reach the end of a small airfield within moments. Safety is also the reason of the two different switches, this action might not fail.
For touch and go the cruise control is continue on.

Cees