I noticed you're very particular about billet parts, but not particular on the material.
That makes all the difference in strength.
Billet CAN be stronger than forged, but only if you use very particular metals and heat treating.
For the most part, forging parts of the same material (assuming said material can be forged) win hands down compared to machining from stock.
Forged parts have grain flow, which adds considerable strength and reduces stress risers.

Problem with forging is that you need a large market to distribute the high cost of initial tooling...but once the tooling is in place, you can make thousands of parts rapidly and at a low cost compared to machining.
So while I'd like to see forged parts, it's not a reality and we have to settle for machined or cast parts.
The only way we could get forged strength out of machined or cast parts is by using superior materials that are compatible with the process, so that's where you need to focus rather than which parts to make.
Transmission gears and components out of maraging or trip steel, bearing supported rear brake lever, lightweight cushion lever for the 250, titanium axles and steering components, redesigned cylinder with nikasil plated aluminum bore as opposed to steel sleeved, and an externally adjustable stator plate to retard timing for starting.
That by itself is probably way more than what we'll ever see built for our LT's.