yes, we always leave a small gap between the braid and the slot, mostly for reliability but for both reasons stated.
when we need to pull up braid which has been aggressive-type contact cemented down, a big hot soldering iron iron works. we use an old Ungar 90W, usually turned down a tad with a lamp dimmer to tame it a little. use No solder on the iron (usually a sacrificial element), just lay it on the braid til it starts to smoke a little, then start to pull the braid up and push the hot tool along ahead of you. we also use this method on commercial tracks (same recessed braid) along with a roller to re-glue it when a piece sometimes lifts. (overuse of braid juice can contribute to this.) the hot iron melts the glue nicely, for either purpose.
special double-sided tape from SCC in lieu of glue is also used around here (recess painted first, I believe), but I haven't tried to pull any of that up yet.