I'm think about buying TSW4 on my pc. Already have on my PS4 but want a system upgrade without moving to the PS5. I have many route DLC that I've slowly collected from tsw2020. Question being am I able to transfer these routes over to my pc edition of the game without paying extra (expect what I'd be paying for tsw4). I don't want to loose any money that I've spent so far as that would really suck. I have a DTG live account so maybe I could transfer them via that? Just want to spend extra unneeded money is all.
... which is fairly obvious. Why should Valve or Microsoft provide you their with their service (file download, updates) if you have paid Sony for that? Steam gets 30% of each item sold for providing the service. If you have not bought their provided content, you won't get it. It does not matter if the publisher (DTG) is the same.
Yes, all routes purchased on PS4 also grant entitlement to that route on PS5. One thing to note is you can't bring in-game progress with you, not that you could transferring to PC either, but worth making you aware.