I'd tend to suggest more heavily using the FBX Format today... in fact I'm a little confused why the Asset Packs that TGC Sell aren't in said format.
Autodesk developed the FBX Format specifically as a way to have a "Common" Scene / Object Format between all of their products (given they basically bought the 'Big 3' Game / Film 3D Packages, at least until Blender became a popular alternative; which is amusing given it started off as competition to Dark BASIC Pro and Unity... still technically can, but the game engine is woefully out-of-date now lol).
It's typical to use FBX for "In Development" Assets., then switch over to something like GLTF for Release (assuming you're not using your own / engine specific format) as these are what most Development Software and 3D APIs support by default today.
In essence replacing the .X / .FVF and .SDKMESH Formats from Microsoft; that were created for the same basic purpose.