I try to describe w/o revealing product - move in any direction till someone shout 'stop', then go back to where you came from.
if this operation works, all is OK.

MEMS gyros and acceleration are not exacting devices. The lower the cost the less repeatable and accurate they tend to be. the cost can be the equivalent of the HW to receive GPS

From the bit of playing around I did with such devices a few years ago I would say that successful application of these things requires -
- calibration will that be needed when the only use is as above

monitoring of the inclination of the carrier platform (tilting) how critical for up to 25 degrees? this could be a problem.

- temperature monitoring and compensation will that be needed when the only use is as above consider temp constant during the above operation but not the same when doing same thing next time

- and lots of software. not an issue (mass market)

thanks Mike

Erik