I also think that some software prevents them from starting normally. It's hard to determine what hangs startup, lots of software i know works only at 386+. Also, maybe problem of conversion is connected with 5.25" 360k images on 3.5" drives, as I remember I've chosen them for BM configuration.
I were able to write your image with both Ultraiso and WinImage without any conversion. Both variants work, but give error at country.sys.
SPEED.EXE works, BM45 condiguration works.
In addition, I've left EMT utility for some time and it gave no errors. So, those 2048k really work.
But I am worried about the CPU.
It works at 8MHz but its temperature is rather high. Almost 70°C, i think it's even more because that thermocouple has large surface area. 70-85°C is max operating limit for 80286 by specs, but it's the slowest CPU and it's so rare that i couldn't find any other users.
And those strange problems with Turbo and memory recognition...
In fact, I can use those 2048k but with very strange and specific configuration.
As I remember, you also couldn't get more that 3072k even with 6x1Mb SIMMs?