FWIW, the UK has, in the past, released war stocks of Hi-Power pistols, mostly Inglis ones, to the surplus market. I used to have one, painted in Suncorite and all. I doubt they would do it again though in the modern UN arms non-proliferation world.
I have a lot of friends who spent time outside the wire at KAF. The guys who trained a lot with the BHP will tell you that if you have reliable mags (a big "IF" in the CF during some rotos), the gun worked just fine.
Typical practise is to carry with empty chamber, safety off. Under combat condition, fine motor skills are not to be relied upon, so even if you carried in Condition 3, you might flub-up taking the safety off. The guys would typically run a single point sling and if you need to transition, you let the rifle fall to your side, draw the pistol and #### the slide with the weak hand in one fluid motion as you present the pistol forward to fire. It's actually VERY intuitive and easy to do with practise and is a more reliable way of bringing the BHP into action under stressful conditions than operating the safety lever.
People often equate range-use of their pistol of choice with what it would be like to use in combat. This is just laughable. When the lead is flying, you want VERY VERY reliable and you want operation that requires as little fine-motor control as possible. Also, if you go striker-fired, I suspect you would not issue troops the Glock 17 commercial trigger. Likely the military would issue the New-York trigger for the same reason the NYPD does. With the BHP, the gun is not loaded until you fully intent to put a hole in your enemy. With a Glock, for example, you need a lot more training to ensure carry safety with a chambered round.
I half expect if the UK stays with the Glock, the typical opord will stipulate carry on an empty chamber and they will load upon drawing, similar to the current BHP manual of arms.