What was called Shadow RAM on the BBC Micro was a bit different to what's described here - it was a technique to have display memory to be paged outside the normal memory map to allow more space for programs.
I think what you're describing might actually be what the Acorn 8-bit world called "sideways ROM/RAM" - the 16K between 0x8000 and 0xbfff was paged and different ROMs (or RAM, if you had the right add-on hardware) could be selected to select different pieces of utility/system software (eg filing systems and BASIC).
However, at least one peripheral I'm aware of for the BBC Micro did do the "copy ROM code to RAM then page out the ROM" trick this is talking about. The 6502 second processor had a small ROM containing startup and basic OS code. The hardware passes writes through to the RAM either way but there's a latch which initially puts reads through to ROM. The first thing that ROM does on reset is copy itself into RAM - you can see the original source code which was recently discovered in GitHub[0]. I'm not quite sure why it did this though.
I think what you're describing might actually be what the Acorn 8-bit world called "sideways ROM/RAM" - the 16K between 0x8000 and 0xbfff was paged and different ROMs (or RAM, if you had the right add-on hardware) could be selected to select different pieces of utility/system software (eg filing systems and BASIC).
However, at least one peripheral I'm aware of for the BBC Micro did do the "copy ROM code to RAM then page out the ROM" trick this is talking about. The 6502 second processor had a small ROM containing startup and basic OS code. The hardware passes writes through to the RAM either way but there's a latch which initially puts reads through to ROM. The first thing that ROM does on reset is copy itself into RAM - you can see the original source code which was recently discovered in GitHub[0]. I'm not quite sure why it did this though.
0. https://github.com/stardot/Acorn6502TubeROM/blob/master/src/...