Most of the world doesn't equate to blast something with to shoot something with a gun, unless of course the definition is predetermined by the context, ie: blast it with a gun. A blast for most of us normally associated with an explosion, blasting at the quarry for instance, my examples were merely of types of devices we normally associate with blasting, explosives. No we don't have C4 or explosive bolts, what we have do are explosive limpets, limpet "mines."
I agree that most of the world understands that 'blast' means more than just to shoot something, although I also feel that most of the world will colloquially include 'shooting with a gun' among the various definitions of 'blast', if only due to the global influence of Hollywood.
I should also point out that during other ship-to-ship engagements, a player can use guns and other explosives to blast open a cargo hatch, so it is not unreasonable for a player to assume you could also use these methods on megaships.
The hatch breakers are explosive devices, limpet mines, we select the target, the hatch, they attach to the hatch then explode, blasting the hatch open. Hence the use of the word "blast" in the description.
Sorry, I may have missed it, but where in-game does it say that hatch breaker limpets explode? The only descriptions I see are in Outfitting:
Control unit that can program a blank limpet to hack an unshielded target's hold, causing cargo ejection.
And in the Pilots Handbook, under Piracy:
Hatch breaker limpets are used to crack open a target's cargo hatch, releasing a portion of the cargo inside. Hatch breakers have a speed of 300m/s and can pass through shields; they can only be stopped with point defences or electronic countermeasures.
Following a successful scan of the target ship, a pirate selects the Cargo Hatch sub-target. The limpet is then deployed, where it will attempt to latch itself on to a target's cargo hatch. If successful, the limpet will pry the hatch open, releasing cargo for collection.
There is no mention of hatch breaker limpets acting as specialised explosives.
Aside from all this, I feel the OP is making a broader point here that, since the
only way to open a megaship Escape Hatch is to use a hatch breaker limpet, this should be made clear. Alternatively, make megaship hatches destructible through conventional means to increase options for the player.