Thanks.[In each case the act involves improvisation but a context is established and a framework etc].
exactly the same for the Blues scale and the Pentatonic major scale, regarding improvisation.one has a   structure of six notes and one of five.
so here improvisation is not totally free, freedom is allowed, but within certain rules, restricted to certain notes, related to the chords.
it is not generally accepted to mix the blues scale and the pentatonic major, willy nilly,.
However using the pentatonic major scale for the tonic and the blues scale for the sub dominant is considered acceptable ,or vice versa.