I have used Flash Drive based boot media for my Linux box. But when I started using and SSD drive instead, my builds and boot times were much faster.
Setting up this post to show someone that asks what I use.
I used to use (and still can) use a flash drive, and I moved on to an MSATA using an SSD Connector, but MSATA drives are a little pricey, so I ended up using an SATA SSD with a USB connector. It has the benefit of a case and a build in extension.
Here are links to the products
USB SSD connector, this one supports UASP for $8.99
https://www.amazon.com/gp/product/B07S9CKV7X
256 SATA SSD $34.99
https://www.amazon.com/gp/product/B01K8A2A0E
If I have time, I will post how to build the USB boot disk, it is more than just a build disk for a Rocky 8.5
Weight: 355.6