Yes, the two locations seem to be the same.
We're on the same sheet of music now. Yeah, I never noticed that that was also Baldwin Hills on the east side of that Kenneth Hahn State Recreation Area. That ridge line is the western edge of the eastern section of that bedroom community. Baldwin Hills is at the northern edge of those hill. South La Brea Ave runs right along that ridge line.
So, as long as we're agreeing that it's 400' (I'm actually calling it 450' along the point where the Malibu-San Jacinto sight line crosses it) at a distance of 20 miles, we're working from the same data. The only thing you might still want to correct is the distance to San Jacinto. JTolen has it at 120 miles on his graphic, but he cites the correct distance of 117 miles (617,760 feet) in the video. And that's what the distance maps out to be also.
Okay, here it is with your numbers (I haven't checked whether it is 117 miles or 120 miles -- JTolan's map lists the locations at over 120 miles away):
Earth Curve Calculator:
https://dizzib.github.io/earth/curve-calc/Angular diameter calculator:
https://rechneronline.de/sehwinkel/angular-diameter.phpFull View of Mountain Without Curve
g: 10800 (Full Height of Mountain in Feet)
r: 617760 (117 Mi in Feet)
= a: 1.002 degrees
Round Earth Amount of Mountain Hidden Behind Curve
g: 6937.2487 feet (Amount hidden below horizon according to Earth Curve Calc with elevation of 150 feet over 117 miles)
r: 617,760 (117 Mi in Feet)
= a: 0.643 degrees
1.002 - 0.643 = 0.359 Mountain Visible Above Earth Curve
Baldwin Hill Height using 450 feet (Your midpoint number -- there are elevations between 400 and 513 feet)
According to earth curve calc, at an elevation of 150 feet, over 20 miles, 16.6866 feet is hidden
450 - 16.6866 = 433.3134
g: 433.3134
r: 105600 ft (20 miles in feet)
a: 0.235
If the mountain is 117 miles away, with a hill height of 450 feet:
0.359 (Visible RET Mountain 117 miles away) - 0.235 (hills) = 0.124 degrees above the horizon
If the mountain is 120 miles away, with a hill height of 450 feet:
0.312 (Visible RET Mountain 120 miles away from last post) - 0.235 (hills) = 0.077 degrees above the horizon