If you are doing it just to hide collision polygons in the layout editor, then of course, it not worth spending hours turning collisions for each tile in each tilemap. It's much easier to move grass and trees tilemaps to another layer and toggle its visibility.
If you feel confident editing raw project files, you can modify objectTypes/tilemap.json - disable collisions for a couple of tiles, save the project, open that file in Notepad++ and you'll see what to do. However, if you really have 150K tiles, this change will probably add many MBytes to your project size.