May sound a daft reply, but i found this with a new pair of Brasher boots i bought years ago.
The first pair i bought, lasted donkey's years, and were as comfortable as my slippers, but the mid section eventually collapsed and called it a day.
Well, a new pair was a must, so a visit to Crickhowell Adventure Gear in Brecon, and i tried on a new pair.
The new ones looked more substantial than the old pair, but looked identical in appearance, and felt heavier, but just as cosy right out of the box.
Well, after several months in wearing the things, there was little give, or molding to your foot shape and contours like the originals, and the rubber sole, was simply lethal on wet rock.
I can remember clambering up the South face of Pen Yr Ole Wen in them, and it was like ice climbing in the things, i was slipping dangerously about in the things.
After a bit of research, i realised Brasher had changed their boot manufacturer, and they were now made in Italy, to higher standards than the original, but the new boots were nowhere near as good as my slippers.
i very much doubt experimenting with different socks will help, a boot should be comfortable, especially after extended use, and if your toes are becoming sore, then its usually down to the inside construction of the boot, something that we cannot see.
We instantly know when trying on a pair of boots in our chosen size, that their comfortable, as any rubbing or discomfort usually shows itself afire walking up and down a showroom after a few minutes.
I may be wrong, and possibly barking up the wrong tree, but the discomfort to your toes is being caused by something inside the boots, possibly the way the boots constructed.
Boots that have been worn with great success, for well over a year, should not really suddenly become items of torture.
Theres something near the front of the boots, that are causing pressure on your toes.