This is the trackball I use at home. It is a beige CST2145-5W-RC laser trackball made in 2017. CST sold their line of trackballs to Pi Engineering in 2019, and they discontinued all except the black case color.
I had a custom cue ball made with the emacs logo by someone on Etsy. It was a drop in replacement since CST trackballs are 2.25" across.
At work I use a black L-Trac trackball made in 2020. It came with a backlit blue ball, but I disabled the LEDs with a firmware patch and replaced the ball. I made back and forward buttons for it with the same switch tester, but the buttons are facing up on this one. The Logitech Ergo M575 next to it is connected to my docked laptop.
I installed ball bearings in both of my CSTs. The stock rollers are fairly smooth, but the ball bearings stay smooth with heavier balls. The guy who makes them has two sizes, and the normal size raises the ball slightly higher than the stock rollers, which causes issues with tracking on multi colored pool balls, but works fine with the stock balls. He sent me a low profile kit to test, and that worked perfectly with all of the balls I've tried. I'm using one of the larger rollers along with two of the stock CST rollers in my trackball at work, and that keeps it in the right range for the sensor while still rolling smoother than stock.