From the last week's check on the data bus, it looks like there's some resemblance to whatever other dump that comes from this website:

https://forums.bannister.org/ubbthreads.php?ubb=printthread&Board=1&main=7205&type=thread

One of the posts mentioned about a dump from another cheap NOAC console:

E000   D8         CLD
E001   78         SEI
E002   A2 FF      LDX #$FF
E004   9A         TXS
E005   A9 00      LDA #$00
E007   8D 00 20   STA $2000
E00A   8D 01 20   STA $2001
E00D   A2 02      LDX #$02
E00F   AD 02 20   LDA $2002

And here, from the recording of the data bus earlier:

78
D8
A9 00
8D 00 20
8D 01 20
...

It could be a startup code, and this varies on ROM to another ROM.  I'm not familiar with 6502's assembler - I might need to try to have the cheat sheet (6502 instruction set list) ready on my side and read it.

I'm now trying to dump the entire ROM and try to dissect it further. It is not gonna be easy, I admit!