Since it sounds like front engages less (being an open diff, I guess they use the brakes to bias torque between sides), I'd go there.

In my opinion, the concern over tire replacement is overblown, especially with systems like Audi uses. Subaru uses a full-time system, that would be more concerning, but even there I'm not so sure any more.

I'm sure your LSD is some kind of hydrostatic, that was Audi's claim to fame from the start. Hydroststics don't care one whit about different wheel speeds.

Even a Quaife (torque-biasing using gears) wouldn't really care all that much, and it would effectively be engaging all the time... Which they kind of are anyway.

Clutch-based LSDs (old style, just springs and plates) would be a concern because it would cause more wear there, but you don't see those on road cars. Modern clutch-based diffs like Bendix supplies to Honda (and other companies) wouldn't care, since each rear wheel is independently (wet) clutched, and the clutches are electro-hydraulically controlled. It would simply compensate for slip, like it's already doing all the time anyway.