MANAGP can only speak for myself but FR taxi limits are 30kts in a straight line and no more than 10kts in the turn. These are straight out of Boeing.
Had it once at STN where an EZY 737 was in one of the cul-de-sacs and we were taxing on one the main taxiways enroute to the hold for R05. The taxiway from our stands is virtually the full length of the runway in a straight line.
He was to give way to us and taxi out. The cheeky s*d read back the clearance and threw in "after the speeding Ryanair"
A glance at the PFD showed I think about 20kts. Hardly excessive on a straight mile and a half taxi.
Everything is not always at it seems!
Have myself said as an aircraft blurs past on the taxiway- "he aint hanging about" but have said about a lot ofl airlines. As for FR 30kts in the right place is ok by the company.