Hope we could get some scenario packs for Tadami Line like on this video with different painted DMU and also diesel locos.
Scenario packs are not done by DTG themselves, but by third-party developers. Since DTG does not even do Japanese routes, you would be hoping for a route developer to either make their own packs or allow others to do so (they may not allow it). I'm not against seeing scenario packs, more to do would be nice. The fact there is so little lowers the value of the DLC in my eyes.
I am not using worksshop things as it always give me problems with the game so it ends up that I have to reinstall the whole game
Error messages and it crashes before it even has finished the loading so at the end I have to reinstall the whole game. I do not even dare to install 1 workshop as I had enough of the crashes and it takes around 3 hours to install the game again.
Here is my suggestion. Unsubscribe from everything in the Workshop (anything downloaded will be maintained), but you can create a private collection to store your items of interest in before actually unsubscribing. Once they are all cleared, try running the game (reinstall if you have to). After everything is fine and functioning, make sure you only subscribe to one or maybe two items at a time if you subscribe to anything, and you can always unsub afterwards. With minimal subscriptions, things should be able to load. You can then use it without the game crashing or having problems.