-1 for how its described in OP.
Instead of "repairs taking time", one could put the station/planet/market location on cooldown after performing repairs, or disallow repairs (because hot plasma is being fired all over the place), then again, why, its a bit annoying if someone is fighting and you dont even care you just want to fix your junk.
Then again, if the only reason is to reduce cheese tactics in some other game design, its better to tackle that specific design rather than make workarounds to fix cheese.
Never had issues or thoughts about how "broken" instant fix is, enemy can do the same by suddenly spawning a fresh fleet on players face.