ICO only means ICO only. PNG is not ICO, is it?
That's a very good point.
I understand your frustration, but as been said several times...... until something changes, there is no other library for PNG dock icons. They are not allowed in the Misc Icon library. And come to think of it, the Misc Icons library didn't exist until long after the ObjectDock library.
I've said it before, the Misc Icons section was meant for additional add-on packages for Icon Packager. Unfortunately the excellent 'icon a day' series opened the floodgates for people uploading single icons.
The Object Dock section was for all OD related items. No-one could foresee the huge number of icon uploads we currently get.
The whole thing has got messy and blurred. It's up to the 'powers that be' to sort it out