https://store.speedtree.com/speedtree-in-2019/
As the years go by access to these kind of tools becomes more and more out of my reach.
Not for hobbyists that's for sure. Moreover, exporting to other software seems to be limited to game engines.
That's where the money is I suppose.
Speetree 8 Cinema does export these modified meshes to most apps including TG. The ST Game editions are specific to a particular game engine (UE4, Unity, Lumberyard). Of equal note in the link Rene provided is the intro of the ST Engine for Clarisse (with other DCC apps to follow) that eliminates the need to import Alembic cache files for wind motion. These files can be hundreds of GB's that then must be pushed thru the pipeline and usually requires a new export from ST if changes are necessary. ST Engine provides a run-time solution from within the host app and allows changes to be made within the host app without re-importation. And for the Game engines this capability requires a more expensive license type. IDV has aimed ST at the Game and Movie industry from inception and it's not surprising that the pricing is not friendly to hobbyists. The subscription model in this instance can be used to advantage: UE4, Lumberyard and Unity are 'free' and the ST version for each is only $19 US per month (renewable month to month), use the program to build your assets, test in the game engine, switch your subscription to 'Cinema' ($200 US for 3 months), export all of your created assets to where-ever with plenty of time left to tweak as necessary in ST. Not cheap, but given the capabilities to create hundreds of quality assets, not bad either.
19 dollars a month is a good deal, but 200 dollars just to be able to export assets doesn't strike me as such. On the other hand, for some studios that may not be a problem.