The colourfastness/longevity of acrylic paint on stencils

Here is what I've found so far:

• There was one really excellent article on reddit about using acrylic paint to print on fabric.  The author was a textile manager for decades and was translating techniques to the home user.  I'll include what I can remember.  It has helped me so much why things work or don't work, and basically nailed it that acrylic paint is totally valid, much to the dismay of all products out there that want to tell you they're special, such as fabric paint, or fabric medium.  The paint just needs enough of the binder molecule to do its work of adhesion to itself on the fabric.  And furthermore, what you typically buy ready-made with print on it is probably acrylic anyway.  Professionally, I think that the acrylic (or whatever it is) has a more flexible, rubbery base while what we buy for painting canvasses has a stiff finish.  Hence, when we've accidentally splashed house paint or canvas paint on our clothes, it becomes stiff.
• Yet, stiffness does become soft after enough washes.  And notice how you probably never heat set it?  Yet the accidental paint is now firmly on your now-old-work-clothes forever and will practically never come off.  So... all things are possible with acrylic paint.  The question is how it is applied.
• The airbrush does wonders and is my favourite technique.  Its application is so light and fluffy it makes subsequent embroidery so a breeze.  Not to mention so fast at covering a large area (once you get familiar with the set up, machine bits, etc).
• You do need to water down the paint to get it through the airbrush sufficiently, but the thicker it is, the better it is for your paint's adhesion.
• It's practically possible to wash of nearly all the acrylic paint within the first day or so after applying the paint.  Hot water, soaking and soap does an even better job than cold water.  However after a few weeks or months of drying, this is really difficult to do (even if you have not heat set the paint).  You can use these properties to your advantage, depending on what you want to achieve.  Note: on testing a highly diluted paint solution, it still washed off after being dried for weeks and months.  It really does need that binder molecule to work.  Cheaper dollar store paints tend to have poorer materials.
• Heat setting is nevertheless a very important step for longeivty of the paint when you want to really try harder for the paint to stay on the fabric.  You can feel the difference after heat setting (especially if you've used an airbrush).  It no longer comes off as a powder if you scratch it with your fingernails.  There's no real rule as to when you heat set it, just as along as the paint is totally dry.  But for simplicity, leave the paint on for a few weeks before you heat set.
• There are several ways of heat setting at home.  It just needs to be super hot but at the same time not burn your fabric.
• iron requires around 10 seconds on an area on the hottest setting your fabric can handle
• oven - still up for experimentation, but around a few minutes at 180 degrees celsius 
• clothes dryer - around 45 minutes on hottest setting.
• I think that if I had a clothes dryer machine, I would choose that option for the evenness and for the fact that there's an electronic servant doing the job for me.  Hopefully when we build a new house and solar panels I can change to this technique.