I don't know if it was intentional or not, but before version 3.0 when the hotbar would fade, the items still showed up without the number of items. I actually liked that effect because it seemed newbie friendly. Wondering if its possible to bring that back?

That "feature" was a bug if you ran Auto HUD together with Sodium some of the time, so it was not intentional. This is the first time I've heard of someone actually wanting it. I will consider adding it as a proper feature.

Would you want the items to stay at full visibility or get slightly translucent? Personally I'm leaning towards the second option.

Thank you for your consideration! There are transparent hotbar texture packs, but I still want a custom hotbar texture

Definitely slightly translucent, so it can be a little more immersive

I added it in version 3.2. :)

Go to Component settings, under Hotbar the latest entry ("Fade-out limit for hotbar items") can be set to something like 0.3 or 0.4 to achieve the effect.

It will also draw the stack counts now.