I have seen 120 PSI in parks, also seen below 50.
Proper set up
Park, regulator Long hose, filter, short hose (Sub regulator if you feel the need) RV
You are correct that 100 + will blow the hose. so that's why regulator first.
on sites where I need dual regulation (I use a different filter now)
First regulator set 60-70 PSI protects hose and filter. 2nd at 50 PSI protects the RV
NOTE: I do not use those 3/4" Cylinders I use a Watts. or Zurin "Whole house" type. 3/4 Inch with hose adapters.. Valterra makes a good one too.
Why Two Regulators??? Well the first filter I used seriously restricted flow. The one I use now is much larger.