In 2008 I converted my EA81T wagon to RWD. It already had the stronger EA82 5-speed transmission swapped in. I also have a clutch type rear LSD and 205/60/13 Yokohama A048 tires. I knew the risks going into the conversion and so I generally only did "RWD" activities in the wet/snow/dirt or other low traction situations. By babying the car I was able to get the RWD conversion to last about four years.
But the whole point of the RWD conversion is to have fun, right? Burnouts, doughnuts, drifting, etc. The rear wheel drive system on these cars was only ever meant to hold 40 horsepower or so. Once you direct the engine's full torque to the rear, the RWD transfer gears become a weak link and will shear teeth like its going out of style.
You'll end up stranded with a ruined transmission, a non-op Subaru, worn out rear wheel bearings (because they're the wrong style for sliding sideways) and an empty pocket.
(But it is fun while it lasts!)