Obviously a core issue with gameplay is forward spawn placement, as any engineer can place a spawn instantly so long as the area is valid, and the only way to destroy a spawn is by a player physically attacking it - which can then be immediately replaced.
I would fix this by:
One; giving officers the ability to remotely destroy a spawn via the spawn menu. A special decision could be made by officers who click the forwards on the map which would allow them to instantly remove it without cooldowns- allowing the officer to communicate with nearby engines to place a new one, rather than spawn jumping and hoping for the best. Officers still could not place a spawn, as that’s still only available in the sapper menu.
Two; give the engineers a cool down for building spawns similar to what already exists for destroying them. The biggest issue with spawn jumping for forwards is that - in the minute or two it takes to make it back to the desired spawn location after destroying an old forward, especially with engineers who don’t know what a “sunk cost fallacy” is - the engie who built the original forward is likely to immediately replace it, while the person who destroyed it has to wait a significant amount of time to destroy it again. Simply giving engies a cooldown would prevent that feedback loop from happening, perhaps it could be scaled with how often their forwards are being destroyed - if an officer had to break your last three forwards, then maybe your time out needs to be longer.
And as an aside - laying a large translucent red or green grid over the map that shows valid forward locations while holding a forward spawn as an engie would help with what becomes frantically looking for a place to place one while dodging enemy fire. When you select it from the sapper menu, the grid would layer with the ground texture - valid spots have a green grid, invalid are red.
Lookin forward to playing the update with +200 Steam hours💪