I’m not sure about streaming new scenarios, but I would recommend modifying existing scenarios. My resource has done exactly that.
If you don’t want things to spawn, check the NoSpawn flag. I went a little excessive and threw things under the map so I wouldn’t have to see them but, the ones with lines, IDK, i’m not knowledgeable on.
Also, my resource requires gamebuild 2189 (Cayo Perico) or higher due to the scenario points being taken from that DLC, and my own personal game files.
I haven’t bothered to do the latest DLC as, the scenarios work fine for me and if I want more stuff, I just open codewalker, click scenarios, go to where the new scenario file is, modify it simiarly to the old one (manually and painstakingly)* and stream that.
Hope this answers your questions.
You can force your FiveM server to 2189 or higher by reading my tutorial