A little more in depth than speculation. It's half bad, and it's half good. The actual truth lays somewhere in the middle. The MG+ is a great chassis, unfortunately the ancillary components leave something to be desired.
Removing the board is a Can - O - Corn. Runs and drives fine, and the voices in my head are gone. The board weighs next to nothing. This frees up a ton of room for snugger body work, or a front screw post. I needed both.
The part they wont tell ya. Changing the motor takes skillz, and or "secret/hidden shunts" as seen in this photo. Never seen or heard of, these "hard" shunts are what makes the MG+ motor and board into a single, stiff, module; which can be pried in and out of the chassis, but so's lil Johnny can swallow it.
The MG+ uses these tricky little shunts to extend the current path from the motor lugs, out, under, and through the mind control board. They wont easily de-solder at the comm lug because of the mass solder they use to attach the shunt to the lug. One really has to try hard to muff the board removal at the end of the shunt.
At a glance, the residual particles on the motor looks like they used a spatula worth of soldering paste on each lug; which might explain how they got that much solder x 2, to pole vault onto the shunts without melting the comm box. (note the above photo)
When the motor is removed from the board, clamp the board firmly, latch onto the brush hanger with a hemostat, heat the solder and pull. They pull right out. New lead wires are easy to install. Both the extended motor shunt and the shoe hanger are already tinned. Dot dot dot dot ... done!
Affixing a NEW motor to an existing board is an entirely different story. Care has to be taken to not over heat the comm lug and melt/displace the brush spring and lug by re-melting the plastic factory retainer button in the comm housing. I would sooner dispense with the board altogether and affix wire leads as above, using either the existing factory shunt on a viable factory motor, OR simply tinning directly to the comm lug on a new motor.
I'm dubious of successfully undoing whats been done by the factory at the comm housing.
Crown gear and wheels pressed onto "gnarled" axles renders them all ruined and useless for exchange or re-use. Note that I intentionally didnt use the appropriate "knurled". Ghastly stuff.
Is it a disposable chassis? For the normal end-user, yeah, 'fraid so. One is not intended to work on or modify the MG+ save for tires, shoes n springs, and clapping your hands in apology.
Me, I'm just stubborn to a fault, and grateful for something to play with. If I dont like it, I just scribble out side their lines and doodle over onto the margins.