Freestanding Iron Ladders have no collision, unlike every other ladder. Here is a tiny video demonstrating the issue.

latest.log Pastebin link

Forge 47.3.0
Quark 4.0-460
Zeta 1.0-24

The only other loaded mods are Embeddium, EMI and Better Controls (modifies sprint/crouch key behaviour), but the issue occurs without those as well.

This appears to be intentional

I thought of this possibility (considering Quark adds seemingly collisionless ropes), but it just seemed a bit weird to have what is, in theory, the most solid ladder to be the one ladder in the mod without collision.

Should I close the issue?

No, we'll wait for Vazkii's comment. I agree that it is strange.

Introduced by iThundxr in fd5a744, looks like a mistake