Don't forget that Chelsea Wilkinson posted here (
viewtopic.php?f=1&t=7825) about adding BBC basic to a Ben Eater build. Here's a link to her Github
https://github.com/chelsea6502/BeebEater , there hasn't been much happening for awhile. As mentioned I got this running on Rich Cini's SBC2.71 ( a variation of Daryl Rictor's SBC 2.5) This runs only in text mode using the ACIA, with 32K (less a page of I/O). I will have to compare with your version @jgharston.
I would like to get this going on Grant's Multicomp also. While it's been some time I do have EHbasic and FIG-Forth running on the Multicomp (using the Cyclone II FPGA) as well. I do not have a save/load for using the SD card for EHbasic but Forth uses the SD for save and load of it's screens to a separate area of the SD card under the forth block scheme. For those interested, Plasmo has EHbasic and a 9 digit Microsoft basic running under DOS/65 on his CRC65.