I keep destroying new tubeless tires!
Sounds like you are running your tire pressures WAY too low or high. If you are experiencing tire failures due to "larger ruptures/slashes" that's indicative of a pressure issue. 

If too low, and you hit a root/rock too hard, the tire will deform too much and you'll strike rim, thus compressing the inside of the tire against a sharp surface and/or fold back on itself to create a weak point on the tire surface. 

If tire pressures too high, the sidewalls and treads are bulging more and thus more prone to failures from rock/root hits. Also, when pressures are too high, the sealant is incapable of sealing any holes due to interior pressure pushing the sealant out too fast or possibly even evacuating all of the sealant.

There is a "Goldilocks", not-too-high/not-too-low pressure for tires that allows them to deflect enough off of roots, rocks, and trail chatter but not so much that you strike the rim on those or risk blowing sealant out. For my use, at 172lbs weight and hard pedaling; that pressure is about 21~24psi on 29x2.3 tires w/ about 3~4oz of Orange Seal inside. I will occasionally finish races with little bits of sealant visible on the tread of the tires where it experienced a small puncture and sealed as intended but not lose so much air that it affects my handling.

I race singlespeed MTB and run exclusivly Schwalbe tires with their snakeskin sidewalls (thin), and their Speedgrip compound. The current tires I installed back in May have 353 miles on them with zero flats and won my regional XC series as well as placed me 9th in USA MTB National Chapionships. I typically get well over 1,000 miles out of a set before swapping them out. 

Hope this helps; best of luck.