I believe
@roberthu 's comment (that you are replying to) is strictly in the context of the time
after a pine has crossed the "ready for anything" line.
The same is true of
@River's Edge 's comments about what to do to techniques-wise (reducing sacrificials/leaders, wiring down, fertilizing strongly). These are things to do once a pine has crossed the "ready for anything" line.
To be wiring and pruning pines and getting reliable budding requires all the vigor ducks lined up in a row. The root system has to be in youthful expansion mode. Needle length during domestication should be trending longer than it was in the wild (depending on where a lodgepole came from..). Tip shoots should be producing multiple terminal buds. And above all, total foliage in the canopy should be increasing, should be lustrous, firm, and sharp. Water retention time should also be dropping noticeably-- if a pine is drying out the deeper parts of the soil quickly, that is probably a sign of vigor. Once you have brought a pine to this stage you will always know it when you see it.
So regarding "
2 years", or the question I think you were asking -- When exactly can you begin to try to induce more interior branching on a collected pine?:
In my experience, the timeline for a pine to be in a "ready for anything" state after collection is
wildly variable and strongly tied to various factors (specifics of how collection went, your pine horticulture skills and implementation, your recovery setup, luck of the draw, soil moisture observation skills, etc etc).
It's so variable that I personally wouldn't include ponderosa and lodgepole in the same conversation about the topic, because lodgepole can sometimes be ready to go in 2 years after being collection, but there are ponderosas that aren't ready for anything for far longer than 2 years after collection. This can be especially true if that ponderosa has to be repotted in stages and started out with a very stringy / gangly / sparse root system.
If you are good at judging risk in pine work you might do some parts of Frank's recommendations early in order to set up the conditions for budding (light exposure, hormone balance). For example, with a lodgepole where I am very confident that I can apply wire safely, I might wire branches down before the ready-for-anything period has fully arrived.
The more vigorous and young they are out of the ground the more you can jump the gun. The more you lean on things like bottom heat after recovery, the more foliage you leave on the tree during recovery, the more that second or third year might yield an unambiguous vigor signal. All pine work is ultimately based on feedback from the tree in the form of vigor and surplus.