Sidewall is only one component of it for towing
In the early days of over sized dia wheels (folks here used to laugh at
them as low rider types) and low profiles (low aspect ratio)...the tire
offerings did NOT support LT class very well.
What there were, were mainly from OEMs and tough if not impossible to
find replacements from independent (non dealer) tire shops
Today's offerings do have decent LT class tires of higher load ratings.
So your question and answer is almost a mute point as long as you stick
to the proper load range for 'your' TV's ratings needs
You have a +8K GVWR, so OEM spec'd 'LT' class tires
So stick with LT class and of the min load rating according to your
drivers door label
Going over sized will dictate either reprograming the tire rev's per
mile for the computer's look up tables, or just living with the speedo
being off.
Torque-management of the tranny will an an issue if you don't change
the look up tables to the correct rev's per mile (tire OD)
Just stick to the OD of the OEM tire for your vehicle and the re-engineering
of the over sized tires will have the tire engineers bake in the metrics
for sidewall strength...unless you like to do the re-engineering...