Diversity in messaging is good, so being yourself and speaking your truth is good.
Being emotional in your arguments and testimony can be good, as long as you are at least a little sympathetic.
Coming across as crazy as bad, and coming across as threatening eventually becomes illegal and that I think everybody agrees is quite bad.
(The calculus changes if the law passes and then opposition becomes a matter of civil disobedience rather than civic participation.)
We have a very Democrat electorate. If gun rights get linked to Republican-party talking points, then it becomes a red vs blue issue, and the argument will be lost along the same percentages that Republicans usually lose elections. The math shows that arguments in favor of gun rights must be made to appeal to Democrat voters. 100% of Republican voters and at least 20% or so of Democrat voters must be convinced that firearms prohibitions are a bad idea.
Luckily there are people who believe in gun rights despite being registered Democrats who would never vote for Trump and who would roll eyes at any claims of stolen elections or vaccine conspiracies. (like me)
So how do we convince Democrat voters that gun rights are good? I think it's a really good idea to listen to what the Democrat senators said who opposed the bill or voted yes with reservations.
1) They don't believe in a justice system stacked against the "little guy" or mass incarceration. This bill could make tens or hundreds of thousands of citizens prosecutable as felons overnight. The bill is worded ambiguously enough that we might be felons without knowing it; enforcement and interpretation is up to fiat of police and the justice system. It'll bog down courts! It can lead to unfairly targeted policing against the poor! The rich won't be affected!
2) They are afraid of crime. Citing a concern regarding rising crime rates or potential organized crime is good rhetoric. If they say "but we haven't seen that kind of crime here", a rebuttal is "well we haven't seen those sorts of mass shootings here either".
3) They revere hunting rights more than self-defense rights, for whatever reason. Support for gun prohibitions diminishes if shown it'd negatively affect hunters. On the islands where deer or pigs are a recurring ecological disaster, this can be tied to an environmental argument.
4) They support cultural tradition to a fault, particularly Hawaiian cultural tradition if not so much white mainland US cultural tradition. I hate to say it and be so cynical, but if testimony consisted of a dozen of the most kanaka people in the state passionately detailing how this bill would threaten their way of life and sustainability, and that they've historically been shown that they can't trust the government to protect and provide for them, then how many transplant Democrat voters would still support the bill?
5) They vacillate like the wind and have deep logical incongruity on this, but half the time they don't trust the police. So why should police have weapons that nobody else has? Why should police have a monopoly on the tools required to defend our communities?
6) They have other priorities. Do we want to get bogged down in new legislation that has massive constitutional concerns and will generate immediate lawsuits that the state would need to fight against? We don't have the money nor the time; it's more important to fund education, rebuild Lahaina, retreat from sea level rise, make sure we have enough renewable energy, etc.
I am pretty firm of the belief that a white man from the mainland (like me) lecturing on the historical theory of the 2nd Amendment is going to sway zero Democrat voters, no matter how correct and eloquent he may be. I'll always make the argument but I don't expect it to win over who needs to be won over, at least not in the short term.