How to display only a few duplicates?

I believe that is already in the the Build you have

Go to the Album Browse screen…Duplicates set to Yes in Settings

Right Click on the First Version of the Album that you wish to make a “Set” from

Then simply click on all the others that you wish to join that Set

Then go to Dropdown box in top right hand corner of screen

Choose Group Duplicate Items from the Menu

All X Albums that you have chosen will now be in that Set

Now Turn Duplicates off

Click on the Album cover that you just grouped into a Set

In the Album Detail screen under the Cover, you will see an “Other Versions of this Album” button

Click on this, and you will see a list of all the Albums you’ve just grouped

Roon will default to making the Highest Res version the Default…but as you can see, you now have the option to make an alternative version the “Primary” version for that Set