There are a lot of SFP modules on sale nowadays that better dissipate heat and are easier to configure. In order to achieve full compatibility you need access to MIB files.
The ITU G.988 specification defines them as follows:
A protocol-independent MIB describes the exchange of information across the OMCI. Clause 8 lists the managed entities and illustrates key relationships between them to implement some of the important features that may be offered by ONUs.
During registration in addition to SN and password, ONT also transmits Vendor id(SCOM), ONT Version(SCOMFGS202v1), Equipment id(FGS202)
#Managed Entity 256(ONU-G)
256 0 SCOM SCOMFGS202v1\0 00000000 0 0 0 0 0 #0
#Managed Entity 257(ONU2-G)
257 0 FGS202\0\0\0\0\0\0\0\0\0\0\0\0\0 0xa0 0x5345 1 1 64 64 1 128 0 0x007f 0 0 48
More in-depth information in the document
For your firmware, it is possible to view MIB after image extraction 0x100000-0x2A0CE7 and endiannes change
user@SFP:~# xxd -e -g4 extracted.bin | xxd -r > reversed.bin
user@SFP:~# strings reversed.bin > reversed.txt