Wondering whether there is a difference between the (potentially subsided?) module provided by an ISP and one that is procured from independent vendors, or the pin 6 issue being a general violation of the SFP MSA instead?
Could not find a data-sheet for the module that exhibits the pin layout/definition but if indeed violating the SFP MSA it would explain why it does not work since sfp-bus.c and sfp.c adhering to SFP MSA conformity.
Supposedly it is not necessary to fiddle with the hardware but instead correct the respective GPIO line to change the offending pin for compliance. Probably gpioset from gpiod-tools will be useful for that purpose.
Incidently stumbled upon this blog [3] and there is no mentioning of needing to fiddle with the hardware to get the module working a in switch device, though not clear what sort of OS that switch is leveraging.
[3] https://vincent.bernat.ch/en/blog/2019-orange-livebox-linux