Not sure if you've looked into this but you can ditch Bell's router with one of these:
https://store.10gtek.com/1-25g-media-converter-sfp-slot-with...
Or a non-copper equivalent in your case. You just need to use the VLAN IDs that Bell expects, see https://www.reddit.com/r/bell/s/uUltTdyqFC
I did end up ditching the modem since I wrote the article. I ended up using a TP-Link 8411 router though. Having everything TP-Link has its benefits for observability and maintenance.