None beadlock tyre pressure

I neither have nor want beadlock wheels but I do have higher load rated all terrain tyres. At the parkwood meet I was running on 15psi and it was great but in terms of the load rating I was only actually 6psi below what the tyre would recommend for road use. This is obviously accepting the tpms having a fit. What I'm looking for is what is the lowest pressure I might consider without popping a bead off? I know there's a lot of variables and freak occurrences but as a ball park figure is 12 safe or even 10?

I have 235/75R15's on stock rims. I run them at 7psi off-road and have never debeaded a tyre. 

So 10 on a 205.70 should be good as long as I keep my head on straight.

Mine on BFG MT 235-75-15 on stock alu rims gets down to 3-6 PSI or 0.2 to 0.4 bar as i use for a measure. Bear in mind that cheap pressure gauges may have large errors but I unscrew the valves and reinsert them when I am happy with the bulge on the bottom part of the tire and measure the pressure.
Usually I keep a bit more air up front than rear because that is where the most risk of ripping them off is i guess. I have never lost the pressure. (as far as i know.)
I have however often lost the balancing as I suspect the tire rotates on the rim a bit so the balancing weights on the rims loose their position according to the tire. Driving to the offroad events is ok and on the return trip, a wole lotta shakin sometimes. I air up for the road of course.

Edit: But I do suspect my tires have recieved damage from running that low. There is this strange pulsating/oscillating sound from them now.  

 

As is often the case just because a bfg mud will stand it it doesn't mean that my radar renegade necessarily is going to do the same. I think I will try 10 and see where I am at.