Two Independent solar systems rather than upgrading old system

bens993
bens993 Registered Users Posts: 1
I have a 4.8 kw system which is 10 years old and the installer is out of business. It is working but my demand has increased and I want to upgrade it. I cant find anyone to upgrade the old system. Its not recommended apparently. What are the disadvantages to upgrading the existing system? I have Enphase M250 micro inverters, I got microinverters so I could expand the system. I really dont want to have two different monitoring apps. Any recomendations? Im in San Diego so I have to act fast before NEM 3.0 takes effect.