Leave it. The figs grow at the last 6 inches of the branches, the more branches, the more figs.
ppeatfruit Self seeded? That's impressive, especially if you're in the UK, as the ones we grow here are ones that don't need the fig wasp to pollinate before developing fruit.
Of course, if it is self seeded, then it's come from a variety that develops seed, therefore it comes from a variety which needs pollination, which is a problem in the UK because we don't have the fig wasp.
I've got one that came from a cutting given to me by a friend in the Algarve. I've had it for about 10 years, every year it develops figs, but they never get beyond walnut size. I've come to the conclusion that it needs the fig wasp, so I'm planning to ditch it and get my pot back. Haven't yet managed to bring myself round to doing it.
All this is to say - I don't think pruning will make any difference to fig size. My fruiting fig doesn't have bigger figs in years where there are fewer figs.