Until recently, certainly in RAF use, the 100 kt limit applied to single AFCS flight, but if you switched the 'good' system off ie AFCS out, you could use the VFR speed limit ie 150+ kts. Not sure how this fits with the Yaw divergence of A models, but I thought it was to do with the protection against DASH runaway. On a single system you don't have the protection of the other DASH backing off in the event of a runaway, hence the 100 kt limit. If you have no DASHs to runaway then the speed could be unlimited but very tricky to keep under control. What model are you flying?