Word is Lycoming approves of the use of Tricresyl phosphate as an oil additive.Even better, they like the autogas STC to keep the lead out. All of my towing was done on autogas and our chapter C140 was much happier on autogas than 100LL.
I would check to see if any gas additive settles out after some time before using it...like in a glass jar. Might cause a problem. Cars get shaken up daily. Planes, not so much.