As of 27.0.12, controllers in Railjack still have a couple issues:
Still no keybind for tactical map, although the controller now at least works once it's opened with the keyboard
LB can't be rebound (gives an error that it has a "melee stance action" bound to it)
Move Down/Dodge/Blink share a keybind (default LB), which causes issues with the drift maneuver when piloting; although it works after the recent patch, it means you have downward momentum anytime you use the drift.
Also some weirdness where if you bind Move Down/Dodge/Blink to a different button, it also appears on LB in the control scheme as well as the new binding, but the drift only works on the most recent manual assignment, even if controls are reset. (Eg. If you manually bind it to Y, the controls list Move Down/Dodge/Blink on both LB and Y, but the drift only works when pressing Y. After resetting controls, Y still triggers the drift and LB does not [with the downward momentum mentioned earlier], even though it says N/A n the control scheme).
Probably not a big deal, but swapping between controller and mouse when piloting/on a turret does not work properly, the sensitivity is all over the place and the reticle "snapping back to center" behavior for controller does not change.