fromelf --bin truncates trailing 0xFF FILL region from scatter file — is there a way to preserve it?

Tool & Version: Arm Compiler for Embedded 6.21 (fromelf [5ec1f200]), Keil MDK

Background:

I have a scatter file with a FILL 0xFF region at a specific Flash address (0x6E70), intended to reserve space for a
"keystore blob" that will be written by a post-build merge tool. The region must appear as all-0xFF in the output
.bin file so the merge tool can verify the slot is blank before writing (Also incase if un-merged bin was mis-programmed into MCU, the firmware will not mis-read the previous programmed information).

LR_LOADER 0x00000000 0x00007000 {
ER_CODE 0x00000000 0x00007000 {
startup_M2L31.o (RESET, +First)
.ANY (+RO)
}
ER_KEYSTORE_BLANK 0x00006E70 FILL 0xFF 0x90 {
}
RW_IRAM1 0x20000000 0x00009800 { .ANY (+RW +ZI) }
ER_RAMFUNC 0x20009800 0x00000800 { rmc.o (+RO) }
}

Problem:

The FILL 0xFF region is correctly present in the .axf file — confirmed via fromelf --text -v, which shows:

Name : ER_KEYSTORE_BLANK
Type : SHT_PROGBITS
Addr : 0x00006e70

However, when converting to a flat binary with fromelf --bin, the output .bin is only ~13 KB. The ER_KEYSTORE_BLANK
region (which is entirely 0xFF) is silently dropped from the output, because fromelf --bin trims trailing bytes
that match the erased Flash state (0xFF).

Question:

Is there a fromelf command-line option that forces the output .bin to include all regions up to a specified end
address, regardless of whether the trailing content is all 0xFF?

I reviewed the --help output (which is minimal for this licensed edition) and tried --bincombined, but that is
intended for merging multiple input images, not for controlling output padding.

Workarounds I am aware of but would prefer to avoid:
- Post-processing the .bin with a Python script to pad to the target size
- Using --i32 (Intel HEX) as an intermediate format and converting separately

Any official parameter or recommended approach would be appreciated.