So whenever I see so many workflows on the frontend, I get a little nervous. Your user will likely experience a long loading time. You’re rightly giving your user some feedback with the alert, but there’s a lot of work to be done on that workflow that checks 6 different conditionals in order to perform changes.
I figured out a way to do what you’re trying to accomplish with just one step in the front end: states

When the user changes the value of a toggle (in my case, a dropdown), I would update the state:

*Note that height feet and inches needs to be converted to decimals. I would also store this value in a state irrelevant if it’s feet or inches, or cm.
Then at the time of creating a new User Attribute, I would save the values as the user entered them, and save their measurement system per item like this:
*Notice that system fields are just yes/no. In my case, it would only be “yes” if it’s imperial.
Then I would send step 1 to a backend API WF for “processing”, meaning, to convert all values that are set to imperial into metric if imperial = yes. In the backend we can have several steps but wont affect the end user’s experience.
The benefit of doing it this way, albeit a little more “complex” is speed. We’re giving users a near-instant experience when saving their attributes.
Hope this can give you something to consider when building this for scale. Of course, if you’ve found something that works, that’s great too!