I have a 12"  .308 based SBR that my plan is to use on pigs out to 200y. Would a Vortex Viper PST 1-4x make sense for this sort of rifle versus i MRO or someother non magnified red dot? I am thinking the illuminated circle and dot would be easy to acquire upclose and the available 4x would be useful out past 100y. Thoughts?

Most 308 only drops 0.2 mil with maybe a 0.2 mil wind@12-14 mph at 200y.  Not something to worry about relative to minute of pig.  That said, I've never regret having a magnified optic, but i don't shoot in low light, and a 1x dot will give better light transmission.

I have a 1-4pst on a 8" blackout, I like it because that round has a lot of drop and and crap ballistic coefficient so the reticle is relevant within reasonable shooting distances <300y.  Your rifle being 308 and expected shooting distance is around 200y I'd go red dot.

Dedicated pigs in low light @<200y - I'd go red dot.

Multipurpose rifle 308 capability at 200-500y - A 1-4x pst would be hard to pass up.

for hunting i always prefer magnification: if your target is not well visible or partially covered by the enviroment or if you wanna choose a specific target in a group of hogs, the magnification can be really useful.

Maybe Leupold's little, light, compact 1.25-4x20mm VX-R Hog with the specific "Pig Plex" Firedot type reticle?  Street price is about $500-$550 or so.  Maybe less if you catch sales or have coupons.

https://www.leupold.com/scopes/shotgun-scopes/vx-r-hog-1-25-4x20mm-30mm

Weighs less than 12 ounces.