None of these have anything to do with what you cited above, which was ICRC's summary of customary law about inherently indiscriminate weapons. Your first and second links here are examining entirely different challenges to the operation's legality, and the third is just some vague assertions from questionable sources like Francesca Albanese.
You could ask ChatGPT and get a perfectly cromulent answer on what these have to do with what I cited. The key theme is indiscriminate weapons used for indiscriminate attacks. Alas, you can lead a horse to water...
Tiny explosives are certainly not the sort of inherently indiscriminate weapons ICRC refers to. You might want to read the article you linked to, which uses nuclear weapons as the main example. The difference in energy released by Israel's beeper vs a modern nuclear payload is at least 10 orders of magnitude.
ICRC is not really claiming that those examples are indiscriminate, they're giving examples of weapons that might arguably or sometimes be considered indiscriminate.
Some booby traps might fall into that category, but this isn't a toy or a banana, it's a device specifically issued to enemy personnel.
There can be separate textualist arguments about Israel's operation based on the specific language of CCW, but that's unrelated to the customary IHL you linked to.
