Bees produce wax when they need it.
This is the best advice we can get.
I has bee amazed about this: When beekeepers buy package bees to Alaska in April, they have not there any flowers or pollen.
Package bees draw foundations with sugar ...in some limit.
I live on same latitude as Anchorage and willow starts here blooming 1.5. Then it is possible to rear brood.
I use to put foundations in the edges of boxes to add ventilation along the wall.
I start my pollen patty feeding at the beginning of April.
When my bees start to make draw foundations voluntarily, they have allready 3 brood generation behind and it is second week of June.
The hive is full of bees and there is much nectar and pollen in nature. They have filled the combs and they want to expand the hive.
It happens at same time in many hives. It must be some common signal when they start to make burr and new combs.