Tell me how I failed, what I did wrong and if I did anything right.

Because of access problems for collecting bags or buckets i started stringing some 5/16 lines 7 years ago. Note I didn't do 3\16 lines as I need to do way more than 15-20 taps per line to access the upper areas. Most of this property has a 30-40 foot drop over 300-500 feet with a lot of flat areas in between. There's no power to the area and I really don't want to do pumps. I currently have 10 lines varying from 15 taps to 50 taps per line. this past season we did 116 gallons out of 405 taps with this setup. Looking forward to your comments
Central Wisconsin.

1 quart per tap isn't bad at all, especially without vacuum. If you want to hit 1/2 gallon per tap, you'll need 1" mainline, vacuum, and strive for 5 taps per or less lateral line. Maybe also consider wet/dry line setup. But on 400 taps on vacuum, consider that you'll likely need more sap storage, a two-post RO with permeate storage, and a bigger evaporator too. Snowballing effect in full force.

You say you didn't use any 3/16 because you needed more taps on each lateral. Surprise, surprise, by design, you should not put more than 10 taps on a 5/16, but with the drop in elevation you can have as many as 37 taps, and on one line I had 42 taps on a 3/16. Sounds wrong? The reason in the difference is that in 5/16 the sap can pass the air bubbles, (really not air, but gases from the cells in the tree, they are why maple trees don't get damaged when the sap freezes in the tree, that gas bubble takes the expansion of the sap preventing cell damage) In 3/16 the sap doesn't pass the gasses, that's how 3/16 developes vacuum on a slope. You said you have 30-40' of drop over 500'. With 3/16 everything over the 30' elevation will have maximum vacuum if using 3/16, with 5/16 you will be lucky to get more than 3 maybe 4" vacuum, if any. I however don recommend 50 taps on a 3/16 line, split it into 2 lnes. From the 30' rise as you go down hill each tap will progressively have less vacuum, but it still won't be zero until you only have a foot or 2 drop in elevation.
You mentioned up to 500 ft long runs, on 3/16 with the drop in elevation you can go 500 or even more length nut on 5/16 you are hurting your production if you go over 100' length. With the 5/16 tubing there's a saying to remember, "strive for 5, never more than 10" Using 3/16 the best scenario is to have 15-35 taps on a lateral.