In retrospect, what are the things you would reconsider in your office design?

I think I'd want to really prioritize humidity control, there are studies on dry air and viral infection.

And maybe make it so every cubicle has a personal HEPA filter(Very carefully, since airflow is confusing and some interventions can make germs swirl around even more).

I don't know anything about management or building layout, but from an interior design perspective lighting is pretty much the easiest and cheapest way to change a space. It needs to be bright enough, diffused to prevent harsh shadows, and of a color temperature people like.

You might even want to have the break room slightly dimmer or warmer, or less diffused, if you want to create a strong distinction and have people not think about work while taking breaks.

If the team has people who would appreciate it and there are windows for it, than having real plants is always nice in an extreme indoor artificial tech environment. They make you feel slightly less like a robot if you're doing pure software work.

Getting some sound absorbing material is good too, but you can figure out if you need it on your own.