You'll probably be alright. 2.8 bar is plenty strong enough to push through a restriction. If your flow rate relied on wide bore pipes under low pressure, the effect would be much greater than your high pressure system.
In any case, I suspect your supply might be capable of more than 25lpm. The water company is only interested in there being more than 7lpm or 9lpm or whatever their standards are. If they get 25lpm out of a thin bore mains pressure only kitchen tap, they're going to say "that's fine" and not investigate further.
Christian.