I found a GP2 tool "gp2 limit" (GP2TracK Size Extender) by Philip Woodward (Woody), which sets the size limit from 62 kb to 65,535 kb. Why is it not possible to build such a tool for GP3 ??!!
I asked Rene'SDI'Smit if he could do such a thing(via GPxPatch obviously). The answer was that GPxTrack already allows an increase in .dat file size which is now limited at 137Kb(don't know what the old limit was).However, something else in the .exe is limiting track size too, which he hasn't found - yet. We live in hope!! I'm just impatient to try Belini's other tracks.