Nice selection of mini's, well done.
Re: the matt coat spray. I have recently discovered that there is no such thing as a genuine matt coat spray, they are varying degrees of satin finish.
After reading that for best results, thinned down acrylic matt medium should be lightly brushed or airbrushed on, I tried it.
Safe to say it was a revelation and true flat results were achieved.
Careful though, not enough thinning or being heavy handed with the application may result in a chalky white residue building up the matt agent is pumice apparently!.