All good info to know. Thanks. I applied the Proofide on warm leather working by the woodstove with just a gentle heat no more than body heat. The good (newish) saddle just needed one application, similar to working with my work boots. The weathered one was "thirsty". It took about 4 applications using small amounts on the fingers letting it set for an hour between coats. The leather now has some body to it and is not greasy at all with no residual to buff and I think it's good as it's going to get.

On the underside I saw impressions where the leather sagged enough to contact the seat frame. I'm not heavy, Holding 160#
Maybe I can tension enough to keep it off the seat frame.