I'm generally in the 25/50 camp, having planes both with filters and without.
But if you burn a lot of Mogas, you could probably go longer. Without TEL to strip the tin off your pistons etc, Mogas will damage the oil more slowly. Still, I follow the 25/50 guide, and change early if it's close at the condition inspection or I have a trip planned that will take more time than the remaining hours on the oil.
I would like to add a comment about sludge build up. These Lycoming engines have a flat bottom sump. When we take off the sump (2 engines, so I'm not a big expert) there is a fair accululation of carbon sediment in the bottom. One engine was opened to install an inverted oil system. The sediment would need to be cleaned out in this case, because inverted flight was intended. But it would be a good idea to remove and clean the sump at some interval, maybe mid-time?