I favor the Maxima as well (blue label “Fork fluid”). Holds up great and is very reasonably priced. You’ll get some guys on here saying to use ATF from the (auto store) and they have for years with no issue and whatever. It is a hydraulic oil just like suspension fluid yes and is generally good at keeping clean. However, ATF weight is quite a bit thicker than your “normal” fork oil. With fork oil the main concern is weight, keeping consistent so your valving stays about the same. For instance maxima 5wt and bel ray 5wt are not the same. Maxima being a touch thinner so could possibly feel different. My recommendation is to buy suspension fluid from a dealer or online retailer most have quick shipping nowadays