I have done a lot of stencil work and paint thickness is the problem causing the stretching- that’s pretty much a guarantee.
Another trick that can stop bleed is to very lightly pre spray the edge of the stencils with a clear base coat. It seals the edges and any seepage is just clear base coat so you never see it. Then very light color. Ever look closely at an original cabinet on these era games... the color is so light is transparent. That’s actually hard to do well with a rattle can.
Looking good. The learning process never stops, I pick up tips and try them and stick with what’s for me, sounds like your doing the same! Good luck!!!