I joined mander.xyz because it has a central theme around the natural sciences. It could possibly include STEM content as well; there is an ongoing discussion about it. The admin(s) are present and very responsive.

For anyone with a love of science and/or nature I recommend it highly as a home instance of Lemmy.

Same here as well. I uninstalled rif and replaced its icon with Jerboa. I don’t even notice the difference until the screen loads 😄