Right now, it’s way too easy to spawn camp enemies. The few moments of invulnerability is next to useless when you can just surround your enemies and place key healing stations or out position them since they have no where else to run. Not to mention on maps like Trainyard, where both teams are in the open, it becomes even easier due to abilities like air strikes, artillery and lasers being another option of easily killing the opposing team.
What I recommend is making inaccessible and untargetable areas, i.e. heightened areas, for people to spawn so the opposing team has a clear disadvantage from just waiting outside. Though at the same time, of course you shouldn’t make it so that the heightened spawn allows sight of most of map.