How deep should my buffet pans be? 4" or 6"

[Polish Wizard]

Thanks to a good friend's efforts, we're building an arch from a lateral file cabinet.
We built a very heavy 6" high I-beam frame to sit on top of the file cabinet, then we cut a hole in the cabinet's top sheet metal for heat to contact the 3 buffet pans we plan to sit into the heavy frame.

We added a horizontal baffle inside the cabinet.
This means the wood fire will be under the baffle.
All heat and smoke will travel to one end of the cabinet, rise through a hole in the baffle, and pass under the buffet pans to reach the flue at the opposite end of the cabinet.

We won't have direct flame impingement on the pans, but I'm sure it will be quite hot.
We're also adding AUF on a rheostat.

My question is --- what depth buffet pans should I buy?
I anticipated 6" so a hard boil won't overflow the pans, it will be easier to ladle out the contents during a boil, and it will be the most side contact for heat transfer.
But --- will 6" be too much side metal and cause sap to burn inside the pans?

Will 4" be a better choice, and still be suitable for a quicker cooking process?

I was cautioned to only have a couple inches of liquid in my pans, which started making me wonder about the depth of pans.

[Super Sapper]

The best bet would be to only have the heat contact the bottoms of the pans with only about 2 inches in the pan. Using 6 inch pans to help keep everything inside. If you have the heat contacting the sides you will get scorching above the sap level.

[Weekend_Warrior]

I use 6" pans and keep 1-4 inches of sap in the pans depending on how close I can watch it. There is a lot of black burnt sugar on the sides regardless of how deep I keep the sap in the pan. The burnt sugar flakes off and gets removed when I filter it. It doesn't cause any issues except to possibly make the syrup darker.

[Jonnie Maple]

I also use 6" pans. And yes you will get burn rings above the sap line. I put u-bolts on the each end to assist lifting and pouring at the end of the boil.

[Helicopter Seeds]

I previously asked on a different thread recently "how deep is your boil?" as I now run three 6 inch and two 4 inch pans. The general response was to keep the depth low, one or maybe two inches deep. In that case either pan is good. But considering a rolling boil will generate splash, the higher depth pan has less loss on the rim. I did change my setup to have the flame focus on the bottom and shield the sides, which has reduced the side burning. I also found pan holders that snap on to the pan at a cooking store.

[TreeTapper2]

I have cooked on these pans for a few years. It is a great starting point. Sap will burn on the sides but that only affects the color clarity of the syrup.
Not sure how sturdy those handles are Helicopter seeds you purchased. I would recommend some stainless cabinet handles that you can bolt right to the pans. When I am finished cooking I pull the pans out and pour them into a bucket. you can laddle them out but you will stand the chance of scorching the bottoms if there is still heat on them.
I used 6" pans and filled them up near the top. That reduced the amout of area the sap will burn. As long as your fire is good and hot there won't be any problems boiling off with pans filled. With 4 pans, one was a sap warmer, my gph was around 6.

[Helicopter Seeds]

They are stainless steel, wrap around the entire rim, and snap in place with a little effort.
I have easily lifted full boiling pans.
I think they were like 9 bucks.