"Unchanged" should hidden by default, or rel should be separated from way

[Kovoschiz]

The map is cluttered by routes when there are changes on the roads, when this is considered an indirect change from their members. Users can toggle it if they want to. Or better, indirect change on way from moved node should be a different option from relation members. Change in line geometry is more significant.
The older design of showing only the object bbox by default also works. Clicking on it shows the entire rel with its members.

[gram2222]

These unchanged object as the member of a relation should not loaded to reduce burden of memory if a relation itself is not changed, as older design

[jake-low]

Or better, indirect change on way from moved node should be a different option from relation members. Change in line geometry is more significant.

Maybe I'm misunderstanding your request, but I think this is already the case? For example, in this changeset, several roads are unchanged, such as the circular roundabout and the road extending east from it. But they are shown in gray, not purple, because their geometries changed (even though the ways themselves were untouched), and they are toggled on and off as part of the "Modified" group, not the "Unchanged" group. The "Unchanged" group contains only parent relations of modified elements, and members of modified relations.

These unchanged object as the member of a relation should not loaded to reduce burden of memory if a relation itself is not changed, as older design

The old design loaded these elements too, but they were invisible until you clicked on a relation.

For example, here's a changeset which changed tags on some relations in the old renderer vs the new renderer. Clicking on a relation box in the old implementation will reveal its members (with no additional network request).

If there are specific changesets that you're seeing performance problems when loading, please post them here and I can investigate them.

[Kovoschiz]

The effect in https://osmcha.org/changesets/164672680 isn't obvious, although you could technically see the restriction=no_u_turn appearing. I'm referring to all route=bus being loaded when the member has an "internal" change. https://osmcha.org/changesets/164791490