DeSmuME has partial DSi emulation. It will use your DSi bios7.bin but may still crash on some DSi-exclusive titles. This emulator does not verify BIOS signatures as strictly, so the “best” file here is simply any 16KB dump. However, for accuracy, stick with MelonDS.
Unlocking the Nintendo DSi: The Essential Guide to BIOS7.bin dsi bios7bin best
If you're looking to upgrade your DSI console's BIOS, we hope this guide has provided you with the information you need to make an informed decision. Happy gaming! DeSmuME has partial DSi emulation