You will find historically that PTC does not update libraries once released.
Creating your own palette library is a very useful feature.
I recommend you add the following to your config.pro so you can place your section (.sec) files in a location outside the Creo folder structure.
That way your section files do not get deleted during a Creo update.
sketcher_palette_path DRIVE:\any-location\...sub-location
A tip about saving sections for the palette function:
Minimize external references. Preferably confined to the X and Y plane of the sketch with only 1 associative dimension to each.
Avoid constraint references that are outside the sketch!
Technically, you should be able to float your sketch around before saving it to your palette location; or add the 2 locating dimensions to your preferred references.
Also make sure your sketch is as "robust" (highly configurable constraints without errors) as possible.
And do not use relations as they are not saved.
