Oh Yeah...

Also how did they make the reality stone into liquid again?

And how did cap react when he returned the soul stone?

So, here's the thing. I'm pretty sure they don't need to return the stones to where they belong, but rather the stones just need to exist in the timeline. (Also, I'd hardly call Endgame a masterpiece)

That was my theory too, though admittedly it's not supported by the Russos or Markus & McFeely.

It’s actually easy, use Time Stone to reverse back the Tesseract to its cubic state, then return the Tesseract and lastly the Time Stone.

What I don’t know for sure is that the Soul Stone isn’t refundable so is Cap gonna leave that Stone there laying on the ground?

I guess if something is non-refundable you can still return it, you just can't expect anything back.

Yeah... the logic about having the stones back where they belong is to restore the energy of those stones to those universes. It doesn't matter how they return, just as long as they do.

I wonder, however, you can drop a certain stone in the ground and work just fine, but dropping the Power Stone...? Wouldn't that be... catastrophic?

As shown in the HISHE video, that 'cinematic masterpiece' is just a mountain of plot holes.