I found my Dex Pad pretty useless, except for the support of the mouse. And today discovered a hidden feature in Windows that allows you to connect to Dex wirelessly, via the S9+...without mouse support. The mind boggles.

I use a power adapter, Baseus which is 35w with USB-C to USB-C and USB-3 to USB-C for my phone and other heavy-usage devices.
https://www.amazon.com/Charger-Baseus-Delivery-Charge-MacBook/dp/B07R4MRQQJ/ref=sr_1_19?dchild=1&keywords=Baseus+charger&qid=1607433438&sr=8-19

For my phone, I then have 2 cables, one that is 5A and one that is 2A (one of those 20k bendable types). I would recommend a cable with 3A or more for intense multitasking.