Confirmed on Twitter and later posted to the RuneScape subreddit, Mod Shauny is working with the wiki team to create a calculator for Gizmos.

"Shauny has graciously given us info on how gizmo perk calculations work in-game, which allows us to build our own calculator. Expect to see a simulator of rolls for gizmo shells using the components you select, if possible a percentage chance of getting each perk, and the possible perks and ranks you can get."
- Jayden, Wiki admin


"We've discovered after seeing snippets of the game code that the placement of components inside the gizmo shell does in fact matter because of the way that the game code is stable sorting arrays. We'll have more info + a calculator over the next day or two."
- Jayden, Wiki admin

That's nice to hear, but what is really frustrating is that only a select few people get this information. Sure, we can look at the Wiki article later once it's published there, but why not share the information directly with all the community instead?

Annnnnnnnd here it is!

https://runescape.wiki/w/Calculator:Perks