Talking about wood repairs,
I am now restoring my staircase and needed to fill some dents, and at first used alabastine pro filler, but that is like all fillers shrinking when drying.
also that took ages to hard, so i looked for an alternative.
I went to the local "action" and bought 2 component "polyester plamuur" i think it was 5€ orso.
anyway, i can really reccomend that, its "workable" for 5 minutes after mixing the instructions stated...
and that was right ! after 10 minutes its so hard you cannot squeez it in anymore, and after 1 cup of coffee (say another 10 - 15 minutes) rock hard !
i could sand it down 25 minutes after apply-ing
So i never use normal "plamuur" anymore..
just take a bit and mix it, apply it, wait 30 minutes and sand it down ..
So action it is and look for a little can that says
"Soriso" 

And it does not matter if its big or small that you need to fill, its rock hard after 30 minutes..

As you can see this is not a thin layer i put in this corner

from they're site:
2 component thixotropic filler based on unsaturated polyester resin. Ecological and free of asbestos and silicone. Use on metal and polyester, marble, deep wood repair (rotten wood) etc. Due to it’s substances this filler is ideal to fill AS WELL as finish materials! 2 in 1