Ok so on the ground by 2026 didn't happen - but i did finally get things to the point where the subframe and diff are now semi-permanently attached to the car. Hooray!
Using the holes in the bed for access I cleaned and tacked in the subframe, using the diff and its sheet metal as a jig to get everything in evenly
Once everything was pretty sturdily tacked - I pulled the jack out from under everything. So far so good! I pulled the CV axles off of the knuckle/wheel assemblies and bolted in the stock lateral links and stacked the tires on blocks to get an idea of where I want the wheels wheels to sit at rest, and this is where the next complication arises - overall things look really good, except the wheels rub on the front of the arches left to their own devices.
I'll need to play with this a little more - I'll either need to do a little bodywork to extend the wheelwells about an inch or two forward, or I may also consider options to move the whole diff/subframe assembly backwards about the same amount, though then i run into other clearance problems in the tunnel. I'll need to spend some time under the car staring at it to figure out which I'd prefer to do. Currently my gut says the latter is the easiest.
For now, however, this still lets me move forward somewhat with the suspension construction. the more pressing issue at this stage is that the rear track is still several inches wide at the back. I loosely bolted the rear coils in place, and that let me get an idea of how much room I have to cut and move things inboard.
I can almost see the end result - II'll be able to scrap the plan of using the impreza towers and modify the stock wheel wells without too much trouble, even though I might want to reenforce them after the fact. Had I known this prior I would have just cut the tops out, but oh well. Maybe if i do another in the future I can save myself the exploratory chopping. Or hell, even if someone else does this similarly - hopefully I can save you a little trouble.
Did a little measuring and this is what I came up with:
Forgive my mixed units and felt tip marker sketch on my mechanics crawler (free USPS cardboard) - but here's the broad strokes: I have a little more than roughly 2" / 5cm of horizontal clearance before the coils begin contacting things they shouldn't. The stock rear lateral links measure about 41cm long bolt center to bolt center, and I'm estimating about 10cm of vertical drop from their frame mounts to the knuckle mounts. if my math is mathed correctly, that means I'll need to shorten the link about 6cm to get the wheel moved inboard the requisite 5cm. I'm going to pull the links all the way off so I can measure them on the ground to double check these measurements - as I've found some adjustable links that would appear to be able to get close to these lengths without much serious modification and if i can do that and save myself a few hours of fabrication, I'd prefer to do that. I've also gotta figure out the trailing arm mount, but that'll come after I figure out the width issue.
Anyways, that's all for my new years update - until next time kids!