[Can't use new features from the new save format]

I use RCT Deluxe from GOG.

The linking to RCT1 is a bit tricky - I linked it and I can use all the RCT 1 Scenarios.
But I can't use the RCT1 Intro for instance.

Will check that out - thank you for the reply : )
Edit: And yeah - now the features properly work.
Thx a lot!

[Can't use new features from the new save format]

I got a running installation of "regular" open rct2 for scenario play and finally decided I want to give the new save format a try, and also installed the "development" version.

I made a custom scenario, however neither the "old RCT1 coloured" paths, nor the "tunnel-landscape options" are appearing when I select them. I can select as many rides, theming objects as I want and I also tested some other new development features.

Can I run both open-RCT2 versions on a system or is it just one or the other?
Or do I have to download the assets for the paths and landscaping features?