MA high / low / open, No its not new, I've been using them in scans for years, but don't often plot them. Agree it’s a tip that should be added to the instruction page for SMA and EMA's, thus making it easier to find.
Agree there are lots of great TA gurus at Stockcharts, John Murphy, Arthur Hill, Tom Bowley, Richard Rhodes, Carl Swenlin, plus a few others and of course Chip Anderson. They all freely share their charts and ideas.
With respect to historical charts going back years in small time frames, (1,3,5,10,50,60 min), I'm not aware of anyone who provides that type of data, most will go back a few days or weeks. You want to go back years on a 1 min time frame, now that’s a lot of data for someone to keep on file.
Just did a test on Stockcharts and extra members can go back about 9 years on the 60 min, 60 days on a 30 min, 20 days on a 15 min, 60 days on a 10 min, 20 days on a 5 min, 20 days on a 1 min. Not sure if it would be the same for any symbol but this is what I got for "GG" Goldcorp.