Last time I used it on a jet was on the #2 on an L-1011 TriStar at Gander taxying out for departure a long long time ago; it was approved practice.
After a lengthly debate with the Captain about use of reverser on taxi, the reverser then refused to re-stow correctly when commanded. The ensuing headaches afterwards convinced me that it's best to leave them until you get to the landing runway!