v2.8.0 brought this change:

Removed show registry name option. Instead, now it shows it when advanced tooltip (F3+H) is enabled

Some players such as myself leave advanced tooltips on in vanilla so that we can always see item durability. Registry name showing in the inventory is just a side effect, but is not entirely needed. I was very glad when this mod, compared to HWYLA, let us turn off mod source display in inventory tooltips such that tooltips didn't always have redundant "Minecraft" text at the bottom (especially if we aren't playing with game-changing mods).

I was puzzled and then sad to find that this registry name mod option is now removed when I updated mod versions. Suggestion 1 would be to allow us to show/hide registry name once again, and for simplicity, a separate toggle option that overrides this to always follow F3+h advanced tooltip toggle instead, keeping the newly added functionality. Suggestion 2 would be to allow us to hide registry name from inventory tooltips if we do not want those either.