It's easy to test. I'll attach unpacked source project files for several TS's animations/objects to this post. Try to open projects files with that demo version.
I believe current trial version actually allows you to do things to some extent, but I'm not sure what limitations they set up for it.
As for how to find out which version you'll need to open projects even before you try to load them in in Spine: open .json file and look at numbers in the first line:
View attachment 4522197
And now you know which version developer used to export the file. Keep in mind that TS's Spine usage is not constant and they change versions from time to time.
Oh and TS also use a not-so-trivial texture packing/unpacking method which I explained here before, but in short - unpacked sprite resolution is much higher than it's used in-game, while included .atlas file use different texture dimensions. I didn't figure it out, so in the attached example textures are upscaled to a required resolution, but you can't repack them properly for game specs as is.