I think you're on the right track. Once you've exhausted the higher payout items (roof, light/heat/cooling efficiency, etc), then windows might enter into it. There may be ranges of configurations where it's a net win. I agree that tall buildings are the best bet, so long as they have south facing windows and some confidence another tall building won't be built in that direction in the decade or two.

I'm not sure what happens when the solar in a window malfunctions. Does the window need to be removed and replaced? Is that disruptive to the people in that office? This is one of the bigger issues with the "solar road" ideas. Nobody wants the utility digging up an otherwise fully functional road to "fix" a bad section of solar. It's disruptive.

I know some companies have decided to build their solar "elsewhere". If they don't have enough roof, they buy land quite far from their place of business and build a quality solar farm and use that power. Sometimes their generation facility is literally hundreds of miles away. They go where the land is cheap and the weather less cloudy.

Electrons are fungible, so if they put X watts into the grid, they get to pull X watts at their place of business. All of the benefits with little of the downside.

Roof and ground solar is easy to maintain because people can work without bothering other businesses or employees. Things can be built without regard to cosmetics, and the maintenance people have a dense consolidated area they can operate in.