Busybox collides with Alternatives of coreutils
Busybox package provides no
Alternatives while it provides links (as part of its package) in places where other packages specify Alternatives.
The second problem we can even see right now is that during update when busybox is reinstalled/updated then it overwrites links previously created by alternatives.
The second problem is that if package having those Alternatives is removed then link is removed as well but busybox one is not reverted in place. This can break some utilities. Upstream pretty much fucked us here. It also seems that opkg has same problems as updater in this case (updater's implementation was inspired by opkg).
Full solution should be https://gitlab.labs.nic.cz/turris/updater/updater/issues/294