you have automatic permission to connect up to 16amps per phase, so 3.68kW AC output on single phase or 11kW output on 3 phase, so they're referring to the idea that if you had 3 phase you could automatically connect a 10kWp system to the grid without needing to obtain permission.
However you may be able to connect this on single phase, you or the company need to ask the question of the DNO via a G59 application, only at that point will you actually know what the situation is, and can then take an informed decision.
Firstly though you need to be sure how much you want to spend, and if it's even worth making the application. No point if you can only justify a 4 or 5kWp system in the first place, either of which can be connected on a standard 16amp limited inverter under standard G83 rules.
