Interesting, we have a professional orchardist saying paint the wounds and someone else saying strongly don't paint the wounds.
I went looking to see what others say, and pretty much everything I found says painting is outdated maybe even a "myth."
from washington state university was this:
Wound dressings do:
• seal in moisture and decay
• sometimes serve as a food source for pathogens
• prevent wound wood from forming
• inhibit compartmentalization
• eventually crack, exposing the tree to pathogens
Wound dressings do not:
• prevent entrance of decay organisms
• stop rot
https://puyallup.wsu.edu/~linda%20chalke ... sealer.pdf
see also
https://essmextension.tamu.edu/treecarek ... ee-wounds/
this
https://www.treedictionary.com/DICT2003/ ... index.html
was actual field research on treating wounds with various different substances and non-treated controls, that did not find any advantage to treating.
The closest to postive I found was
You may use wound dressings if you wish; however, some tree care specialists feel that wound dressings interfere with healing or callusing. A light application of tree wound dressing does indicate that someone attended to the problem and may make a pruning job look better or more professional.
https://ohioline.osu.edu/hyg-fact/3000/3045.html
which basically implies that painting the wound is strictly cosmetic.