There's no shortage of resources available from feminists, trans advocates and medical professionals online
If they're so abundant and easy to find, then why not simply share them? You can also link the other posts that explain your position.
confidently spread their harmful ignorance
If he has such an uninformed position, it should be very easy to defend against it instead of wasting everyone's time by making ad hominem attacks? Maybe we can make the internet a better place by not spewing toxic abuse even if one feels attacked by an opinion, no matter how uninformed it is?
You are defending your ideology in the worst way possible, and believe me when I say this, but you will never convince anyone beyond your closed bubble of why we need to move forward as a society this way.
You don't know the first thing about requirements engineering. Technically, these assault rifles are primarily designed to kill/injure people, it's 100% part of the stakeholder/requirements analysis in their systems engineering workflow.
An airliner is not designed to fly through the air. It's designed to transport people and cargo from A to B within a given amount of time. Flying is just a means to achieve it.