Insulating wooden beams / frame from concrete footings
I don't think the intent should be to separate wood and concrete.  I think that applies to encased wood  such as in footings where concrete retains moisture for some time.  Wood and concrete are used together all the time.
In your case its just wood on a flat surface but it doesn't really do much as it is a flat surface so water will sit there.
The plastic shims would be the best bet i suppose to raise up a bit but it seems you can't use them everywhere and it is a bit overkill.  You can possibly use strips of closed cell rigid?