Made mine with Yellowstone bourbon and a 4:1:1 ratio. Dropped the aqufaba/egg white (personal preference). It came out an excellent drink. I think the Whiskey Sour is one of those drinks that really lends itself to customization to fit one's tastes. I played around with the specs, but it's still recognizable as a Whiskey Sour, just adjusted to my taste.

Replaced Simple syrup for Orgeat ... a even richer drink >:)

Did this already a lot. This time cut syrup as I have Monin cane one which to me is sweeter than 2:1. Still one of the best ones

I used Québec La Chaufferie's Sugar Shack (Rye Canadian Whiskey with maple syrup - picked it up myself in Granby, Québec) and used ordinary simple syrup. Oh, and aquafaba. It was delish!

I’ve taken to using Dr Adam’s dandelion and burdock bitters added directly to the shaker and a splash or two of angostura in the glass. Adds depth and complexity to this bittersweet classic. Highly recommended!

Should I use the same proportions if I want to make a whisky sour with another kind of whisky (rye, blended) or I must change something?

I tried a 5:3:2 formula with Monkey Shoulder (and without egg white or salt) and it is spot on for a lightweight like me. My wife liked it too. Thank you.

I used Liber Gum Syrup for the sugar and egg white and it came out very nice.