For what it is worth, I have a framing plugin coming out very soon that works with Estimator – BUT yes, you can use PB2. I used to use it for my framing until I built the new plugin. My old workflow with PB2 and Estimator was to model all of my framing members – the key is to have each type on their own layer. For example 2x4_SPF (plates, sills), 2x10_SYP (Header), etc. Studs were Components. Then I grouped all of these various layers in one group and put on my wall framing layer for that level. In Estimator, you assign pricing based on the lineal footage in Layers tab – for example, use total LF of 2x4_SPF divided by 16 for how many 2x4x16′ plates you need. Studs can be counted as components and pricing added in Components tab. The new framing plugin works the same way – each element is on a Layer to allow takeoff. Hope this helps.
IF you already have a framing model – how was it modeled? you could always use Takeoff_Length to collect all of the lineal footage of each type easily, just by picking edges you need. Feel free to email directly with any questions to John@estimatorforsketchup.com