MichaelNZ:engedib:You won't need the PPPoE client on the Mikrotik.
Some additional detail is here: https://www.draytek.com/support/knowledge-base/5367
Thanks for that link.
Put another way, can I choose to keep how I currently have it, running PPPoE on the Mikrotik and just use the Draytek DV130 as a pure bridge?
Shouldn't be a problem. The Draytek 120 and 130 we're popular cuz they can do pppoa bridging too, which is unique, but vdsl is pppoe and pppoe bridge is a common config for them.