Text-only reader views are great imo! However reader views and projects like AMP are somewhat controversial for other reasons not related to a11y. Color contrast controls are great too. I like how Twitter does it, with high-contrast mode kicking it into the AAA rating. That said, the site/app should hit AA without any auxiliary controls.
There is definitely wiggle-room in that the difference between 4.5:1 and, say, 4.35:1, at least to me, is nominal, even though the latter would fail to meet AA. This wiggle room is going to vary from product to product. My hope is that the product team at Bootstrap has thoroughly tested their UI with these colors and decided it hits their internal…
As far as I know, the latest Material guidelines (which can be found at Material.io) don’t advocate for or recommend certain text treatments. I can’t speak for the Material team, but from my experience here, it’s more common for us to use sentence case (“Click this button”) over title case (“Click This Button”) or all caps (“CLICK THIS BUTTON”).
Short answer: No.
Long answer: All textual information (including text and icons) should have at least AA contrast over its background. AAA contrast is a nice to have, but not necessary.
Creating a masterdoc is very quick, especially if you use the same template for every project. Re: your Drive issues, you should reach out to support, as I’m not in the best position to diagnose :)