“I am sure I have read that the German “Paris Gun” of WWI entered what is considered space before descending.”
The Paris Gun fell far short of the Karman Line.
I had to look up “Karman Line” and yes it would have been well short of that. It did fly well into the Stratosphere tho.
The Germans figured out that once it got that high, there was very little air resistance which greatly increased the range.