Gabriel, I think it'd be safe, you'd just get a lot wetter, and be a bit more likely to flip.
Not only are the Scouts tubes smaller, it lacks the rockered bow and spray deck. These make a big difference with stability and wave deflection, and IMO for expedition packrafting the spray deck is essential. It gets cold sitting in a raft (I froze my butt off on the South Fork Flathead this weekend), and an open boat would be even colder.
It really depends on usage of course, but the main line boats and a deck are worth the substantial extra $$.
We're both in Missoula, PM me if you want to take my Yak for a spin some time.
Add.: The seat in the normal rafts also makes a huge difference. It keeps your butt off rocks, and just as importantly provides a buffer and spreads out pressure, thus making the floor less likely to abrade. Both very important things, given how likely you are to use an Alpacka in shallower creeks and rivers.