Hey, thanks for reporting this problem
I'm wondering too where that time could be wasted, honestly aside from roboport upgrades (which is a one-time task for each research / mod reset) which is very demanding and may take a long time depending on the amount of roboports on the map, I can't think of anything else that could be causing this problem...
Upgraded roboports behave as normal roboports (they are, in fact, a mildly modified version of the same prototype) so they won't be taking more resources than vanilla roboports do.
The power wires / powerfield come from a dummy power pole which is nothing more than a sprite-less invisible pole placed on top of the port itself. This, again, shouldn't be taking more resources than any other power pole...
Maybe the sensor array upgrade is the only other thing that may impact performances on huge maps, but I haven't been able to test it in such extreme conditions...
Are you sure that screenshot wasn't actually made during an upgrade process? The scheduler should have its own interface showing what is going on behind.
About the wires, do you mean power wires? Unfortunately as i said earlier I use an invisible power pole entity to generate the zero-radius power field that powers the roboport itself, so once this dummy entity is placed it behaves as any other power pole, connecting itself to nearby poles; if it didn't it wouldn't be powering anything.
Normally, the player could un-wire those poles with a copper cable if they please, but since those dummy poles are invisibile this is something that is not possible.
The only suggestion i could give is to avoid using the research altogether. Unfortunately there's only so much we modders can do with entity behaviors (which are coded in the game engine and can't be changed from the LUA side of things), so it's an "either all or nothing" scenario.
Anyway, I'm finding myself with less free time that i used to, so I can't tell if and when I'll be looking into this issue, but thanks again for this report, any more detailed information that you could have may help me track down the problem faster!
Bye!