Hi, I have exactly the same issue!
I am however, leaning more towards using 3x 5kw single phase inverters purely because of redundancy. (Livoltek all in one Hybrid 5kw systems)
Also we are 3 phase at the moment, but there is nothing stopping the municipality deciding they need the other hot lines for elsewhere on the street. (slim chance but possible) You would then become a single phase house and stuck with a 3 phase inverter.....
Will be interesting to see the response from the people that have done this already.
Cheers