I use the mini nuc frames from B Equipment..
https://bee-equipment.co.uk/products/frame-for-double-mating-nuc-flat
which look like Goran's frames.. My DIY boxes use them - they are made of celotex or OSB3 board. If colonies do get too large in a celotex one, bees will chew holes (as above)- but easily filled when empty (I use Tetrion). Gave up OSB - too heavy,
I have overwintered in 5 fame mini nucs using celotex - easy but you need to feed fondant every month in winter...which poses a few weather/access issues easily solved using top feeders with the access hole over the centre frames.. or using a peelable clear plastic cover over the food only - so you don't disturb the bees ..(The latter is preferable in cold winters )
The 5 frame ones are large enough to raise a reasonable Q after being dequeened if the they have to feed only 1 QC
I now make my own frames using Beesy connectors and plywood.