Coir is, IMO, one of the problems with many of the peat-free composts, because it doesn't readily hold on to moisture unlike peat. When you water pots or seed trays, it seems to run straight though. Perhaps adding Vermiculite or Perlite would solve that problem, as they both hold on to moisture?
The usual fertilisers would also have to be added to it, of course.
I think it is probably time for me, to try mixing my own, as shop bought bags have just been so unreliable over the last few years. (Those made from garden waste often seem to be full of fungus gnats as well
)