Holy cow, thank you for this. On that same IBM[1] link, it reads:

Maximum wet bulb temperature (Only LTO-8 and earlier cartridges) / Maximum Dew Point temperature (LTO-9 and later cartridges), all across the board, allowable / recommended / shipping: 26°C (79°F).

In Florida, we like to refer to 79°F dew points as "Tuesday."

More to the point, the time I want those LTO cartridges to earn their keep is during a disaster scenario. The most likely disaster scenario--other than fire--is hurricane. High temperature and humidity, and no power to run the HVAC to mitigate those. (Unless you have generators with fuel to run for days, and your HVAC, generators, and fuel tanks survived.)