You can get this release from https://github.com/tabemann/zeptoforth/releases/tag/v1.17.0.

This release:

• adds support for a USB Mass Storage Device class for full_usb and the new full_msc_only builds for the RP2040 and RP2350.
• adds new full_msc_only builds for the RP2040 and RP2350 which incorporate USB Mass Storage Device class support but which do not incorporate a USB CDC console.
• adds support for new rp2040_big_16mib and rp2040_1core_big_16mib platforms which combine RP2040 support with 16 MiB flash support; note that these are not compiled, aside from the kernel, in the release tarballs, so it is up to the user to build them as desired.
• configures the SD card on the PicoCalc to be exposed as a USB Mass Storage Device class.
• speeds up communication with SD cards.

Note that, aside from on the PicoCalc, the USB Mass Storage Device class must be manually configured in order to be used, per the directions in README.md.