I did some research for ya and it’s true there’s no rule or law that says a hobbyist can’t fly over 400’ in the US. The entire law is 146 pages so including link and relevant info
Sec. 336 Special Rule for Model Aircraft
(a) IN GENERAL.—Notwithstanding any other provision of law relating to the incorporation of unmanned aircraft systems into Federal Aviation Administration plans and policies, including this subtitle, the Administrator of the Federal Aviation Administration may not promulgate any rule or regulation regarding a model aircraft, or an aircraft being developed as a model aircraft, if—
(1) the aircraft is flown strictly for hobby or recreational use;
***(2) the aircraft is operated in accordance with a community- based set of safety guidelines and within the programming of a nationwide community-based organization;***
(3) the aircraft is limited to not more than 55 pounds unless otherwise certified through a design, construction, inspection, flight test, and operational safety program adminis- tered by a community-based organization;
(4) the aircraft is operated in a manner that does not interfere with and gives way to any manned aircraft; and (5) when flown within 5 miles of an airport, the operator of the aircraft provides the airport operator and the airport air traffic control tower (when an air traffic facility is located at the airport) with prior notice of the operation (model aircraft operators flying from a permanent location within 5 miles of an airport should establish a mutually-agreed upon operating procedure with the airport operator and the airport air traffic control tower (when an air traffic facility is located at the
airport)).
Note #2. This means that the FAA can’t regulate the rules for model aircraft for non-commercial purposes, ie fly for hobby. Instead the AMA (Academy of Model Aeronautics) will regulate them. I swear to you I thought they had a rule not to fly over 400’ but they don’t apparently. Still have a VLOS til though.
AMA regulation info (see page 4)