[MCPE-171451] Certain held items appear huge at higher texture resolutions

Various seemingly random items, when made higher resolution in a texture pack, scale improperly and appear huge in the player's hand. This is not a duplicate of MCPE-120618, as this impacts vanilla items, not custom created addon items. No item models or other files were changed for this to happen - simply the texture file. Tested on Windows 10 and iOS. I confirmed that this issue was not present in 1.19.83, so it likely started some time in the 1.20 previews.

In the example screenshot, the string texture has been scaled up to 64x64 to demonstrate the issue.

Expected behavior: Increasing the resolution of an item texture should cause the item to remain the same size, but have a higher pixel density.

Actual behavior: Increasing the resolution scales the size of particular items, resulting in huge items when held. So a 64x64 texture will appear four times larger in width/height than it should be.

How to replicate: Apply the item scaling test pack below, or use your own texture pack where items are at a non-default resolution. The test pack has increased the size of all item textures to 4x their default resolution, and made no other changes. In-game, view one of the listed items below in third person (also somewhat visible in first person).

Impacted items: (these are the items that I have so far discovered, however there may be more)