Thank you!

The bathroom has an exhaust fan, right? Use it.

Think about using Mapei Flexcolor CQ. It's a single component acrylic based grout that is perfect for true color. Like any epoxy or other resin based grout, it does require a bit more targeted cleaning with a scrubbie, or you can get haze. If the concerns that give rise to using epoxy are about mold, or waterproofing, then realize that ventilation is what prevents mold, and a shower should be waterproofed underneath the tile.

Tile is in, epoxy grouted, and the smell was quite mild. We opened the skylight, ran the exhaust fan, and ran a charcoal filter air cleaner as well. Still running, but I can no longer smell anything and my eyes don't burn. We did not use tile on the floor. Elders tend to break bones when we fall on tile or concrete. We used Altro Aquarius over heavy plywood for resilience and for being really slip proof. And it's even kinda pretty.