Agenda - thread hijack, but with some content to address OPs question.
Disclaimer - I'm searching/investigating/inquiring, but have very limited experience with Tow Vehicle tires. Only Michelin tires considered, so feel free to offer alternative brands with better solutions.
Believe the lower profile suggestion came from recommendations to reduce the diameter of the tire to improve the gearing of the vehicle and thereby improve towing ability.
What I have found is that lower profile tires generally carry a reduced load rating. The shift to a LT tire to get more load and a stiffer sidewall is not possible as most are 65, 75, or 85 aspect tires. Bimmer has 255/55R18 tires, which is a relatively low profile and is similar to the OPS size, but a bigger wheel. The closest LT tire is a 255/65R18. That size has more weight capacity, but is taller by about 2" - the wrong direction to achieve the OPs objective.
So, the possible approach may be to look at down sizing the wheel and moving up on the tire aspect. The problem is brake clearance. Will not work for our vehicle, but may work for others. LT 215/85 R16 could be an option for the OP.
Another approach may be to use run flat tires. They do not have a good reputation, but do have a stiffer sidewall and should be an improvement for towing. Never seen anyone recommend this option.
We are looking at the viability of the LT255/65R18. It has a 3000# weight capacity which is about 2x what is required. The inflation pressure is quite high and we are looking for a load vs inflation pressure table. Anyone know where to look. The 16 in LT tires are in the RV data files and may be representative, or not. Would be nice to run at 40-45 psi.
Appreciate any information you have. If you have not chased this rabbit, don't bother. But if you have a solution, a suggestion to investigate, or the location of an inflation load table for all LT tires, that info would be helpful.
Travel safe. Pat