Getting the fullscreen app menu from zorin 16 In zorin 17 is really easy and it involves two extentions.
First step:
Make sure that in zorin apearance, your layout is set to full screen and looks something like this:
**Second step:
You need two install two extentions:
Third and final step - Extention configuration
Once you have sucessfully installed both extentions, you need to open the extentions app which you can easily find in your app dashboard. Then, open the just perfection settings and go to visibility tab, next diable "Workspaces in app grid"
And thats about it!
Note that if you want further customization you can also change other settings such as blur my shell settings to your liking
(As for vertical scrolling you would need to use an extra extention that will give you a custom menu. I believe theese are the limits of gnome's default menu)