To lost model number on 3490 firmware maybe no much effect to functions.
But it is different if you lost on 3790 firmware.
I got 37xx with less functions. (No 3D Building ability)
I flashed to 3490 and got 34xx but I had 3D Building.

It means to lost model number on other nuvi series may not be a happiness.
Except we test and find no side effects on every nuvi series so ergn,41 is a must thing to do.