Three weeks of conditioning should be enough – crack one open!
Update 02 March: I’m seven bottles in now and have just opened an eighth, this time choosing a yellow cap and opening it over the sink in view of my note-to-self made at bottling time. Carbonation was indeed more than necessary but by no means a gusher, and the amount of citrus is just right. I don’t think I could drink more than a pint of this on any given night, but the landlady reckons its fine; not too bitter but a bit on the fizzy side.
Question is, will it hold? I’ve heard that the fruity kit beers are best consumed early because the character fades quickly with time. We’ll have to wait and see.