How does Mom's Box work with swallowed trinkets?

If you complete a victory lap you'll unlock the "Gulp!" pill which lets you swallow your current trinket(s). This basically means that the trinket(s) are destroyed and their effects are made permanent.

I can't find anything about the interaction with Mom's Box (doubles trinket effects) on the wiki. Is the enhancement still applied?

Let's assume I have a "Gulp!" pill, Mom's Box and Cancer. If I use the pill and swallow my Cancer trinket...

• ...I will only get -2 tear delay since Mom's Box doesn't work with destroyed trinkets.
• ...I will get -4 tear delay for as long as I hold Mom's Box
• ...I will permanently get -4 tear delay even if I switch Mom's Box for another spacebar item since I had the double effect at the point of swallowing the item.

Which of these things will happen in combination of those items?

Solution 1:

I've recently had a run with a Cancer trinket, the "Gulp!" pill and Mom's Box.

The 2nd scenario described in the question was the one that happened. The doubled effect will apply/disappear by picking up/dropping Mom's Box.

The same applies to the Smelter item.