normally, the setting would make the name of the item blink, and add an info-text to the description of the item that tell you that it needs to be picked up for the collection page.
There is no setting to display an outline around the item

alright! if that is the case, I am still struggling to get that aspect to trigger.
Even though I have never picked up the item, I see no difference from any other item.

Tested again today as I unlocked crooked penny yesterday, found it for the first time today, and there were no differences. My settings are as follows in case this is user error (likely).

Under the repentogon tab, which I did install:
Hide Uncollected Items: False
Highlight Uncollected Items: True
Highlight Color: Rainbow (36/42)

Show Descriptions On Collection Page: True

Though I will say I am not sure the descriptions are working on the collection page either. What is that supposed to look like?
If its supposed to look the same as in game, then it seems repentogon is likely my issue.

The settings look correct to me, so it should work if you have the latest version of repentogon installed.

The collection page config option works as you have described. If you have it enabled, if you go into the main menu -> Stats -> Collection, you should see the description of the item currently highlighted on that page. if thats not the case, maybe try to take a look into the debug console for any error messages. send the error message here if you can