As far as I know, neither F-Droid nor Droid-ify have this feature. I feel like it’d make it a lot easier to browse the apps available on F-Droid if I could tell it which apps I’m not interested in seeing, so that it could automatically filter them from the displayed results.
The Steam store has an option that allows you to “ignore” certain games, and I’m thinking it’d be nice to have that same feature in an F-Droid client.
There are googobs of apps available via F-Droid.
Are you referring to a bunch of apps in general (don’t want to see them at all for whatever reason - do they offend?) or just those that show up under updates that you don’t want to see?
If the latter then just go into that app’s entry, tap the three-dot menu, and select Ignore All Updates. Done.
Note: On most of my ROMs I use F-Droid Classic. On the couple that have F-Droid they are at v1.15.6 (for personal reasons). I assume the above still applies to current versions(?).