Secondary Explosive Effects or SEE's have only been duplicated in ballistic labs with slow burning magnum powders and 70% or more empty space inside the case. Norma has published data on this.
Hodgdon recommends 60% loads of any H4895 data for reduced loads. That should tell you it's pretty safe if their lawyers let them say that.
Many anecdotal accounts of SEE's can't be verified and can't be duplicated in a lab. The fact is it could have been a double or even triple charge and the evidence has literally gone up in smoke after the fact. Even if all remaining rounds are pulled and checked it doesn't mean the one that blew up the gun wasn't a multi-charge.
The reason faster burning powders are used is because a lower velocity is usually required for optimum performance of cast bullets and that lower velocity will reduce peak chamber pressure. It can reduce is so much so that conventional rifle powders meant for 45k+ psi wont burn properly/completely/cleanly. The use of a fast burning powder that will burn at a lower pressure is necessary. Two rifle powders I often use with cast bullets are H4198 and SR-4759. I also use H4895 or Benchmark but only in certain rifles that I've gotten good results in. I also sometimes use various shotgun/pistol powders for exceptionally light loads but they don't work well past 50yds. I use Unique, Bluedot, Reddot, and 800x. With those I also often use cast pistol bullets to save on lead. One of my favourites is the Lee 90gr .314" SWC. Mine drop .315" and I shoot as-is in 303B and x54R but size down to .311" for use in .308" rifles.
I never use full power load data meant for jacketed bullets with cast bullets because they've never worked well for me. It usually results in barrel leading, keyholes, and frustration.
Personally when loading cast bullets I load one of two ways. I either use a load that fills at least 50% the case so a double charge will be very obvious as it will be filled into the neck or cause the case to overflow, or I use a load that if doubled wont blow up the gun. Most loads with H4198, Trail Boss, H4895, Benchmark, or SR-4759 satisfy the first and most loads with shotgun or pistol powders satisfy the second. That's not to say a double charge wont be overpressure and wreck my brass but only that it likely wont blow up the rifle. I've mostly moved away from shotgun and pistol powders except for the light pistol bullets I mentioned above.
Haven't had a multi-charge yet *knock on wood*
