Hi there ALittle, so sorry for the delay! The CGA4131COM would able to support 1400 MTU and has that as the default. Changing it would be outside of our demarcation but if there is anything else that you need, please let us know!
It's definitely possible that there are some community members with experience and ideas that they can provide, that's what's cool about the forums! We're glad you joined and I hope that you find them useful and that the day goes well in the meantime!