I had a similar problem with xtc[1], a C/ObjC like language for the atari 8-bit. The ultimate goal is to self-host, which isn't as impractical as it seems because the target is an FPGA-based emulator. That 6502 has 1GB of RAM and runs at >100MHz.
But the keyboard doesn't have { so I settled on (( and )). You can still double-up brackets in expressions, but when it's parsing structs or blocks, it will also accept the double-bracket as a delimiter.
[1]: Xtc - a managed-memory language for the 6502: https://atari-xt.com/
