Frozen items are not calculated in the model, as if they didn't exist. Items
turned off are calculated, but not displayed. This has numerous
ramifications, beyond regens. If a block has entities in it that are on
layers A, B, and C, and the block is on layer D, the model will behave
differently if layer D is frozen or just turned off. If frozen none of the
entities in the block will display. If D is off, they will all display,
presuming that A,B, and C are still on and thawed. There are similar
situations with viewports, and 3d models as Longshot described.
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