Very enjoyable map, especially the central hub area with the exposed rocket launcher and the sniper perch. The rocket definitely has the risk-reward going of being in a very vulnerable position but at the same being fairly easy to rocket jump away from. Overall I found the weapon placement to be really good, with every weapon being instantly viable.
The small trench connecting to the lava pool in the central area could perhaps use some tweaking, since I found it to be a flow-stopper to get out of. One possible solution could be to just fill it with magma, mainly because it's cool to jump across lava pits, but also to reinforce the magma element. The area with the beams and alcove next to the rocket could probably be used to serve more of a purpose as well, maybe you could create an alternate path to the next floor or put some vials there or something.
Another area I liked was the narrow corridor with the long window. I can imagine alot of baiting taking place there, due to both exits being easily covered by one player. Other than that the layout was readable and the map-size seems appropiate for the amount of players you are going for, never had any downtime. I couldn't get to the island by the Link Gun, but I assume that's a WIP thing.
Good work!