Upgrading Jeweled Items

Hey, guys! So I was wondering what would happen if I upgraded my lvl 58 mythic belt (Illuminating) to the lvl 61 version (Enlightened). I don't want to wait 24 hrs to put the jewels back on my new belt so I was wondering what would happen if I upgraded my Illuminating belt to the Enlightened belt WITHOUT removing any gems. Will the jewels be lost after the upgrade or the the jewels will still be there in the new upgraded belt. If you've tried or know someone who tried this or anything similar to this situation, please let me know what happens. Thank you!

I don't know about the new items but back when himingleva armor was the best, upgrading it with gems/jewels in it made you lose whatever gems were in it. I have no reason to believe this has changed. If I were you I would be safe and remove the jewels first.

Since you craft a new item using the illuminating belt + arcane shard, I think you'd lose your jewels in the process. But I am not sure, I'd always remove them.
I think it's a new case, a mixture between upgrading an item (slotting jewels) and crafting a new item out of an item+ crafting material. Cinco said [here] when items or materials get consumed during crafting it's not possible to cancel crafting, whereas when you just slot a jewel, the jewel and the item still exist and thus crafting can be cancelled. I could imagine that in this case (enlightened belt) the crafting process of a new item, thus consuming the initial items, could lead to a full disappearance also of the jewels.

Anyway, check stat comparison of Elo belt and Enlightened belt, I 've posted an example [here] and you'll see that it's definitely not worth consuming a shard for the new lv61 belt.