I have one unpowered Personal Residence.

I am planning to build a Power Generator and a Highrise. But, seeing the many bugs that have appeared since the new rule, I was wondering if I would lose control of said planet, even if I make sure to finish the Power Generator first?

1. Make sure the power gen finishes before any flats
2. If you build flats in another city, make sure they have power before finishing too.
3. Do not use the 'makeover with all facilities' for the city slab.

So far, those are the only 3 issues I know of at this time that will cause loss of planet control due to the new power rules.

I take it the new rule does not include pre-existing planet 'holds?' I just read the rules, sadly too late for my recent failed little take over, ... but it seems the 'holds' done previously are still in tact.

Until the time limit is over.

“1. Make sure the power gen finishes before any flats ”

Well... the PR is already finished.

You mean that once a flat is unpowered, powering it up won't give planet control?

Riax, I think the issue is that Isa has control under the OLD rules from the single PR. So if the Power Gen completes first, it powers the PR and there is no control change. If something else finishes first, the control script will run, see that the flats are unpowered, and remove Isa's control.