In a previous operation I worked in, Andergauge VGS's were regularly run in the 12Â¼ section with fairly decent success and relatively few downhole failures (I only remember 1 in 20-over wells). I seem to remember that the biggest issue was confirming the stabilizer setting / status downhole.
Re placement in the string, in general, nothing should be below the motor, unless it is flexible enough to limit, really, really limit, the cyclic stresses that will be imparted to the motor's drive shaft (which is not only one of the weakest components in the motor, but also very difficult to fish).
You should also ensure the tool is serviced, inspected, assembled, and tested in accordance with the manufacturer's requirements. It's not a super-complicated tool, but ...