Let me start off with this
I do not have these tires
That being said it is basically math that you are dealing with when it comes to tires and how much pressure to run
The tire in question has a load carrying capacity of just shy of 2100 lbs @ 44psi
simple math tells us that 1 psi = 47.72 lbs on that tire
not knowing the max GVW of the KJ off the top of my head and being to lazy to go look I will guess that 6000lbs is about right maybe a little high
knowing that the MFG never intended for your KJ to carry more than 6000lbs then you need about 1500lbs per tire
so how much pressure in these tires will hold 1500lbs
1500 / 47.72 = 31.43 ,unless I am wrong is this not what is stamped in the door ,32 psi?
now yes running more will not hurt to a point ,34 maybe 36 psi
also note that this is a C load tire and is made for this size and style vehicle
a MTR is not they were made for a different rig and this is why they need more psi at a given weight
they are an E load tire and should be run at higher PSI but not any where near their max of 80 psi
some place around 38-40 for best MPG to ride compromise
There is no math for airing down or for running bias ply swampers
with a C load radial tire 16 psi and you should do fine E load should be good down to 12 psi
swampers

I run mine at 12 psi off road and 25 psi on ,so far so good
hope this helps