Martin Trautmann wrote:

thanks - I guess I'll give 2-part-filler a try, adding some sawdust from
another knot for a better matching color. I was just in doubt whether
the shrinkage of the knot will differ too much from the other wood,
resulting in cracks later on.

IME, the knot may well shrink and want to fall out a few years from now.
It's also likely to crack, and to want to fall out a few years from now.

--
Michael McIntyre ---- Silvan
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/