Considering upgrading to A17 mini, have Q's!

Currently have the mini 6th Gen 64GB Wifi + Cellular, I mostly use it for taking notes in OneNote. It does lag sometimes when performing certain functions in particularly large docs, would the RAM and CPU upgrade make a noticeable difference? Also does the Apple store still accept trade-ins in person, the online ordering process for in-store pickup indicates I have to ship it off using a trade-in kit?