I would definitely not prune now for design reasons. The only pruning that should happen -- preferrably, at the time of collection -- is to reduce top mass to reflect reduced root mass.
In my experience you'll see the following cases:
- Don't show green when your others do -- didn't make it through winter and already dead.
- Green buds swell but don't fully open, or open but are tiny -- likely already dead. Needs mist and shade to have any chance.
- Buds open with inch long needles, but no extension. Weak, but likely to make it with good care. Occasional mist, protect from afternoon sun.
- Buds open to > 1 inch needles and you get extensions. Healthy trees that can be pruned gently starting next year. Afternoon protection still a good idea.
The main thing I've noticed with western larches is that it can take some time to understand how they are doing post collection. I commonly see them leaf out nicely, without extension, and then have needles that gradually turn yellow in later spring. These trees don't have enough roots to support the foliage, which is why mist helps.
So, I wouldn't do any pruning or wiring until you're through your first season and know that you're in that 4th bucket above.