Using compost early

Would it be OK to use home-made compost created from old vegetable matter and garden cuttings/pruning that's only 90% rotted?
I need to fill a planter, and would like to mix the contents of my compost bin into three times as much compost bought from a garden centre. Ideally, I'd leave it to rot another month or two, but I need to fill the planter now.
It's pretty much mud/soil now, so almost ready to use, but when you turn it over with a fork you see the occasional half-rotted piece of vegetable or cuttings from trees and bushes. Nothing has been added to the bin for four months, and I started filling it 18 months ago.
If I can use it in a 2-feet deep planter, should I mix it evenly with the bags I buy, or use it as a layer at the top of bottom? The bags will be much lighter and fluffier than my own muddy compost.
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It should be fine Tomsk what nature started will finish when you plant it up, and provide feed for the plants you put in it. As long as it's not sour you should be fine. I'd mix it through it will all rot down.
When you say "mud" that sounds like it's a bit wet, so just check it doesn't smell sour, in which case it wouldn't be good to add.
Some things aren't always rotted down completely, such as tree/bush cuttings, hard veg stuff, such as sweet corn husks. Personally I would sieve these out if I was using it in a pot/planter, and put them back in the compost. If your planter is fairly large then it should be ok, and mix it in esp. if it is a bit wet.