Hello,
I ported uLisp-3.3-arm to the Teensy-4.1 board.
This board is very similar to the Teensy-4.0 board (same arm-cortex M7 processor), but it has an sd-card socked soldered and more gpio connectors.
I wrote about the Teensy-4.0 board some time ago here: uLisp on Teensy 4.0.
The sd-card can be used from uLisp for saving uLisp-images and other files (for example: uLisp-code snippets).
I didn’t do lots of test, but it seems uLisp is running on this board very fast.
You can download my modified version of ulisp-3.3-arm from my github page: uLisp for Teensy 4.1
Have fun!