I have a GQ-4X. Everything seems to work well, except opening a BIN file with Read Mode: x Byte of 4 (32-bit split).
I'm using 27c040's (so the buffer size should be 7FFFFh). This works for a standard 8-bit file (Read Mode: Normal), but the buffer size is limited to 1FFFFh when trying to load with the 32-bit split.