Yeah, I bought some aftermarket knobs for my older (first) Hawk as I kept breaking blades, I bought the round style like you have shown.. I personally didn't like them one bit.. I know others love them.. I think I'm just accustom to the standard 2 wing style ones as that's what I like.. I bet I'd like that other 4 winged type you have shown in the next to last photo of it on your saw.. But those round ones made me feel like I wasn't getting a grip on them to get them snugged up good.. so it made me keep over tighten them...
My newer Hawk came with some steel knurled knobs which might have worked out okay other than the knob portion was quite small.. was maybe about a 1/8" larger than the actual threaded part.. and they made my hands hurt trying to grip that tiny little knob.. Thankfully it also came with the standard two wing style and those are what I use on it..