I use Ampersand’s ACEO encaustic panels and they work fine for oils. The surface is much more absorbent so a couple coatings of your preferred gesso is optional.

I tried soho’s aceo pannels and didn’t like them. They worked ok for a while but one day we had a rainy day at a show and some got wet and fell apart.
I sell mine and a lot of people like to collect them like baseball cards. They don’t like the thicker panels because they don’t fit in the baseball card trading books.
I tried watercolor paper and I like it for watercolor and most mediums but for my oils, oil would go through the back. so I found oil paper I think at Dick Blicks and I really like it. I get the 9 by 12 tablet and can cut a page into 10 aceo’s

Actually there are ACEO panels available. They are made by Ampersand marketed under the name of Stampbord. Eighth-inch thick, they are an ACEO sized version of their Claybord panels. If you haven’t painted on Claybord there is a learning curve, as the surface is very absorbent until you get a couple of layers of paint on it or prime it first with gesso. I use these panels for all my miniatures and they are primo, especially if you paint in the classical technique using glazes. Here is a link to them:

https://www.dickblick.com/items/13625-1001/#description