Ok, here is the story: I've bought japanese maple wit a tiny scar on one twig. It was manual "damage". Kinda fresh one, so I didnt make a big fuss about it. I thought that tree wont have any kind of problems with healing it by itself (over time). Initial depth of "scar" was about 0.3 mm on area of 2mm x 4mm. Just a fraction of "bark" was damaged, I'd call it abrasion from my point of view.

As soon as i got home, Ive applied copper based anti-fungus solution on the spot. Just to protect it from fungal diseases. At least I hoped it will.

4 weeks later:

https://zapodaj.net/44f01f27c8d05.jpg.html

https://zapodaj.net/e79e41169902c.jpg.html
https://zapodaj.net/cddcd7a28fd87.jpg.html
https://zapodaj.net/7c4db51a5b98e.jpg.html

On first 2 pictures you can see that the "scar" got thicker. I mean this reddish/pinky bark used to be 0.3 mm wide (previously its color was milky/yellow - looked just like after scratch/manual damage), now its even 1mm thick. The size of scar did not increase dramatically. Only this reddish/pinky bark makes it look bigger. I'd accept that it is the way it heals, BUT: look at pictures 3 & 4, its the other side of this scar. And this is what makes me concerned. Previously, on this side of twig, tree was perfectly fine. No signs of damage nor diseases.

Should I be concerned? Is it some kind of disease? Should I remove the twig?

Thanks for any kind of help.