Hm... "Dude" is fairly male-coded, so shouldn't really be used in mixed company
"Dudette" is female-coded, so adding that might be a good idea
But that only covers the binary genders, so for non-binary I propose "Duderino"
Putting all that together, the address "Dudes, Dudettes, and Duderinos" (in any order) could be the best way to address a mixed group
@Siphonay in Spanish it's a male diminutive but in esperanto it's female. Not sure about any other suffixes that would work better
"Dudes of all pronouns" certainly works, but feels a little clunky to my ear
@troubleMoney as eugen suggested I like "dudes of all pronouns" a lot
@troubleMoney I hereby propose a motion where everyone is called pepperoncino
@troubleMoney Dude, that's just too much. I just call everybody dude, even the women. :P
maple classic™ 
@trinsec @troubleMoney i don't know a lot of people comfortable with that
i know I'm not
@troubleMoney @squirrel Problem with internet is, I am not going to play 'guess the gender'. Sam could be male, but also female. I have better things to do than pondering about one's gender.
@trinsec @troubleMoney yes and calling people you don't know dude is very ham fisted
sorry we don't conform to our views but you are actively offending people by calling them dude if they're uncomfortable with it
@squirrel @troubleMoney People choose to be offended, to be honest. I'm not clairvoyant. I can't predict beforehand if they're getting offended or not.
I consider dude to be gender neutral myself in this new day and internet age. So it also depends on one's views.
Again, if one wants to feel offended, I'm not stopping them...
@trinsec @troubleMoney dude is not gender neutral
asking people or reading bios is not clairvoyance
@troubleMoney @squirrel *Shrugs* Your views, my views. Have fun, hakuna matata. 😊
@ghost_bird oh yeah, other forms of address are available and work well, but I was just musing on the "dude" schema
@troubleMoney the "rino" suffix sounds male to me :/