I had a look at look at emulator source and some cart docs a while back and it looks like 708000/F08000 etc. are safe to use for ROM in any modern emulator.
bsnes from a while ago:
//research shows only games with very large ROM/RAM sizes require MAD-1 memory mapping of RAM
//otherwise, default to safer, larger RAM address window
uint16 addr_hi = (memory::cartrom.size() > 0x200000 || memory::cartram.size() > 32 * 1024) ? 0x7fff : 0xffff;
map(MapLinear, 0x70, 0x7f, 0x0000, addr_hi, memory::cartram);
if(cartridge.mapper() != Cartridge::LoROM) return;
map(MapLinear, 0xf0, 0xff, 0x0000, addr_hi, memory::cartram);
void CMemory::map_LoROMSRAM (void)
map_index(0x70, 0x7f, 0x0000, 0x7fff, MAP_LOROM_SRAM, MAP_TYPE_RAM);
map_index(0xf0, 0xff, 0x0000, 0x7fff, MAP_LOROM_SRAM, MAP_TYPE_RAM);
Older/smaller games without MAD-1 on the cart put SRAM at 708000+ but MAD-1 games don't. The newer/bigger games work fine when reading ROM from those areas. A ROM that is big enough to require the 708000+/F08000+ area should have no problem using it. I tried a SMWCP2 ROM which is 4MB lorom and ROM shows up at 708000/F08000 like it should in bsnes 080 memory viewer.