I understand the reason for this question? but I myself have tested for interference from the Frsky telemetry interfering with the GPS and found no issue? but I have my receiver about 100mm from the GPS. Somedays it can take longer than others to get a fix..
Is it possible to buy an additional GPS module (same one, Mediatek) and attach it to the APM2 without mutilating the existing one on board? For $40 it might be worthwhile to put a GPS antenna back on the top of the horizontal stabilizer to get better separation.