i don't have any sage advice . i've no experience using it on fabric, but on other things ( glass metal paper, plastics ).
sometimes older developer gets more speed + contrast as it ages ...
when you melt it down, only do a small amount at a time, the more you heat+melt it
it tends to fog ... AND while i hate suggesting to use a hardener, you might consider
using alum hardener in your binding agent when you sub your fabric and in your chemistry ..
sometimes liquid emulsion likes to lift + frill and unfortunately slide off what it is painted on ...
i'm sure your guru in your part of the world will know all this, and i'm being redundant
using liquid emulsions is a blast ..