I reported this issue to Lesserkuma, they confirmed that battery-backed SRAM saving may have been broken from v0.11 to v1.0.I have two (2) games to test whether saving works or not.
So I did this setup but to no luck, data retention on the SRAM still doesn't work.
- WarioWare Inc. (2003/SRAM)
- M&L - Superstar Saga (2003/EEPROM) but I've already SRAM patched this one via GBATA.
However, I found out that lesserkuma's GBA multimenu might be the faulty one (I have "battery_present": true).
I found this out by using ArcheyChen's GBA multicart menu and data retention on the SRAM now works properly.
Even the setup that I did earlier works properly as well. Thank you!
This specific issue was recently fixed (v1.1). I've tested and can confirm that saving works properly.