Openflexure is really cool-- I have a couple openflexure microscopes. https://openflexure.org/
Building optically precise platforms with bearings and sliding surfaces is annoying and difficult. But it turns out you can do pretty dang well with applying force to bendy metal or plastic.
Below around 1 micron scales... sliding bearing surfaces can start to get less predictable, and more expensive. People get around the issue by combining different sets of precise and wide-range rough-motion systems. https://www.pi-usa.us/en/
There are also easier options if you spend some time with a specific use case. =3