Have you used basic? Or VTL-2?
I have never used the assembler / editor yet. I use a software assembler on a Windows computer and upload the paper tape image file.
The memory upgrade board is a pretty nice spoiler... A few seconds to boot basic vs 13 minutes with an audio cassette player.
Have you tried your upgrade board out yet with the updated flash monitor? I tested every single upgrade board by booting and loading basic.