No clue what’s best for a scooter. But last time I checked, both bicycle stores and workware garment stores had some nice options. Something like this, and with workwear there’s several different looks and options for every season:

https://www.strauss.com/de/de/warnschutzjacken/warnschutz-softshelljacke-e-s-motion-24-7-3210970-84511-1498.html

On a similar note - I bought white as well as red reflective tape and stuck them to areas of my bike that made sense. I did the same to my helmet.

I have a reflective harness kinda like this with my gear for night riding. Extremely compact, but still gives relatively good reflective coverage.
But obviously it lacks a lot in the neon green/orange part.

FYI - they sell jackets and ponchos that are 100% reflective.

I also recommend retroreflective tape applied to the scooter, front and rear lights, a camera or two (drivers and pedestrians both are waaaay less willing to be abusive on camera and if there’s an accident, you have evidence), and maybe a MIPS helmet with a light built in (or retroreflective tape applied).

You can also look at getting a Hiplok Gold with reflective cover: It’s a cut resistant chain that you can wear as a belt when you’re not locked up.