Do NOT add a white flag in the middle. Look at DP2 maps - maps with middle flags DO NOT get played. Mirror2 had a few brief moments where it was actively played - but that was due to being able to see white flag from base. Camping IS A PLAY STYLE, just like rushing is. White flag makes for awkward gameplay.
Now, honest feedback? This map only has a chance at seeing play in small pubs. It's a tournament entry, so that's fine. But the base is boring. Flag in a flat room in a corner, water just adds annoyance and no gameplay change.
Mid looks like it has POTENTIAL from first glance, but as Jeongwa mentioned - there's no real flow, jumps, etc.. I only am looking at screenshots, but I assumed that big volcano thing was something you could ramp off and get good speed - but Jeongwa mentioned you cannot. If you adjusted that to a form of jump, that could land in a "HBD" pathing into the base - maybe it takes you to a spot that drops behind flag. Move flag more to middle of room so someone cannot just sit directly on flag and never be grabbed on.
Key things: GOOD maps, whether 1 flag or 2 flag, you should not be able to stand directly on flag and have the advantage in a 1v3 to never get grabbed on. Camping is a strategy, but maps should not be made to make camping easy. Even maps like Airtime, Propaint1, the advantage of a good setup is often the 3v1. (not always, but due to recon not being perfect and good timing, at least theres chances for grabbing flag).