noip.com or dyndns.org would sort out a mapping from a fixed domain name to a dynamic ip if it did become a problem. you say it stays good for months but what about if other sites link to you, your IP address changes in six, twelve months and the link is broken. How many of those bad links do we all come across from servers in bedrooms?
Even my £65.00 Linksys firewall/router has SPI, DMZ and a dyndns client built in, it’s linux based as well, you don’t open your internal lan to outside you put your server in a dmz, internet facing, no port forwarding internally. macOS or not. Smoothwall is free if buying a decent firewall/router is a problem for anyone. Just needs an old PC.
Biggest headache and why I found it pointless to host at home is checking firewall logs, snort logs etc to make sure to the best of my knowledge that the server hasn’t been compromised.
Played with Linux like that for a number of years, best just to pay a bit each month for a hosted plan and concentrate on content rather than server maintenance, we all know how quickly a site goes out of date and sporadic updates.