And if soldering is beyond your optimization ambition, there's aliexpress where you can find small USB-PD adapters for most electric shavers. It's little niche innovations like this that drive my ordering flow, not saving a few cents.

For those that want to travel light the Panasonic MultiShape[1] is great as you can share one rechargeable base with multiple tools. It is annoying as it's not USB, but inexpensive cables are available[2] and work great.

[1] https://shop.panasonic.com/pages/multishape [2] https://www.amazon.com/dp/B0CMGQWM1B