Given that, it seems to me that convincing other Houses you could do it - even if you didn’t actually possess such a technology - would give your House a massive advantage.
That could be a campaign in itself - maybe a small and besieged Espionage or Industrial House tries to bluff that they can easily/inexpensively/safely defeat personal shields as a deterrent against their more powerful enemies.
Or the reverse - an enemy House appears to have developed a technique to easily defeat shields in ranged combat. The players are tasked with finding out how they’re doing it, and, if it’s a lie, obtaining some kind of hard proof.
The shield buster plot line is a really cool idea! You would have to literally destroy everything to avoid someone else figuring the tech out later. Any shred of information left could risk calamity again.
As for the science of shields, what ever you want your interpretation to be, I suppose, you would be the GM. How much physics would you like to apply
Shields as an idea are a broken concept. They fulfil the role that Frank Herbert intended in the books well enough, which is to make combat fundamentally different to modern warfare. But the explanations leave plot hole that can have any reader thinking “Wait a minute, if that’s how they work then why not…” and “But what if someone…” after giving the matter some consideration.
This is an even bigger issue with Dune as an RPG setting, because then you have to deal with the players themselves unleashing the same creativity that results on Portable Hole/Bag of Holding ranged annihilation missiles and a Decanter of Endless Water with a Ring of Shocking Grasp around the spout.
Just treat this the way that the rulebook does attempts to combine Lasguns and Shields into improvised nukes- disallow it and tell the players discussion of it isn’t permitted as part of the game’s buy-in. Doing otherwise might result in a cool game, but it will also guarantee a game that’s no longer Dune.
Now, it we’re going to talk about ways to get around shields using basic real-world tech as a thought exercise- let’s talk about flamethrowers. Or a giant garden mister that sprays concentrated acid. Or chemical warfare agents. Or the use of thermobaric munitions.
Let’s talk about why, exactly, you can’t put armour on and then use a personal shield getting the bonuses for both when any HEMA enthusiast will tell you that the rulebook’s excuse about armour slowing you down significantly isn’t even close to accurate.
Basically, Frank Herbert was a visionary who created an amazing setting but nobody is perfect and he really, really ought to have brainstormed his ideas about shield warfare with other sci-fi writers before publishing Dune.
I believe a valid tactic is to slide a pistol through the shield during a fight and fire point blank into the target, and it probably requires less finesse than a two foot blade.
As far as the laser/shield interaction, I suspect Herbert wrote Dune thinking a Laser was a beam of super enhanced or amplified radiation. A shield is a manipulating field. Does the radiation beam hit a shield and somehow feedback into the laser causing the explosion? I think Herbert imagined lasers as super focused and enhanced beams of radiation. But I also suspect it was all for the narrative.
