The enemies will chase hard but it’s definitely possible to get away. They will definitely chase for awhile though so maybe put some points in speed if you plan to hit and run.
Many enemies can use the doors so that will barely slow them down, but I almost got away via an elevator once - left behind almost all the mobs except for one guy that could teleport so I had to run for a couple rooms to leave him behind. The two times it worked only one of my guys managed to get away, but I also hadn’t put much points in speed and I often don’t realise things have gotten bad before almost everyone is dead - my vanguard is chronically in the red.
I am a bit annoyed I lost an entire party to the targeting bug - sometimes when you target the medic’s painkiller ability the cursor gets stuck on the friendly target mode and you can’t attack new enemies. I lost an entire party that way once. When it happened again I had my guys run away (hey that time running away did work!) and I managed to reset the cursor - I think I had to use the painkiller skill but targeted it on the icons on the top left. Anyways, maybe a good idea to not use that in combat until they fix the bug!