Repro Steps:

1. Create a New World on Creative Mode with update_1_20 Data Pack enabled.
2. Get "Smithing Table", any Smithing Template, Golden Boots and Redstone Dust.
3. Upgrade Golden Boots in Smithing Table using Smithing Template and Redstone Dust.
4. Take created Item to hand.
5. Move Camera or walk.
6. Observe the issue

Observed Results:

Armor Parts upgraded with Armor Trims are flickering on sides of held Items. Issue is visible on all camera modes in all Dimensions. Chestplate flickering is visible only in 3rd Person Cameras.

Expected Results:

Held Armor Parts upgraded with Armor Trims are not flickering.