I'm off at college so I've stopped making liveries (for the time being, at least), but I'm continuing to ensure compatibility for the ones I've already published.
The developer probably only modeled the FDM within the nominal flight envelope... If it is YASim that is the only way possible.
Low-level flying — It's all fun and games till someone looses an engine. (Paraphrased from a YouTube video) Improving the Dassault Mirage F1 (Wiki, Forum, GitLab. Work in slow progress) Some YouTube videos
it's worth keeping in mind that the visuals of an aircraft have nothing to do with the underlying flight dynamics - in fact, you can hook up arbitrary 3D models to an FDM, and you can also hook up arbitrary FDMs to any given 3D model.
For things to become plausible, there needs to be an explicit "link" between the two