Whenever I see stuff like this, I think it's a terrible strategy based on Sklansky-Chubokov rankings or just some dingleberry trying steam off a few buy-ins. Either way, I'm over shoving here 100% of the time against an unknown.
Some S-C combo and equity numbers to chew on based on the EQ > 0 for 70bb and above:
Range -- 44+, A5s+, A8o, KJs+ (167 combos taking into account QQ removal)
12 combos - AA, KK - we still have 18.26% equity
16 combos - AKs, AK the two overcards - 56.05%
1 combo - QQ - 50% though we'll either win or lose a tiny fraction of the time.
48 combos - underpair JJ-44 - 81.07%
10 combos - non-paired Q, AQs, AQ, KQs - 67.90%
80 combos - undercards AJs-A5s, AJo-A8o, KJs - 70.09%
That should be a good starting point for you to work on assumptions of villain in these instances. Even if you cut back on the range of hands he likely shoves 70bb with, it's still highly profitable to overshove and get him heads up.
Happy Triple Twelve!