Not only can you replace the clutches in a clutch-type LSD, but you can adjust the breakaway torque easily with the oil mix. The LSD additive you see adds slip, and you can buy gear oil without any to start. Just play with the fluid until you're happy.
Depending on the design, breakaway torque can also be adjusted with a spring inside, which sets the squeeze on the clutch packs. Need more? Put in a stronger spring.
Some of them have a clever way to change bias between forward and reverse (and coasting) - they're known as 2-way or 1.5-way or 1-way. 1-way will be essentially an open diff reverse or coasting; 1.5-way gives some LSD action reverse or coasting; 2-way is the same either direction. The ones I've seen are set by how you assemble it, so it's not hard to change.
While I'm at it: avoid the original Torsen design that has the side helix gears perpendicular to the axle. They are weak. Newer designs, like the TrueTrac, put the side gears parallel to the axle, and are much stronger.
tldr; a clutch LSD is way more adjustable than any gear LSD.