I need to ask you for the last time: Please don't take part in my threads before you buy the e-bike I'm discussing.
Apparently you have no idea what the derailleur is for. If you, however, understand the principle of the derailleur, please tell me what "maintaining a proper cadence" has in common with "motor power".
If you, however, insist on giving me your enlightening advice, please also tell me what motor could be used to replace Specialized SL 1.1 that is present in: Creo SL, Vado SL, Como SL, Levo SL, and Kenevo SL. Thank you.
For your information: Specialized is one of the three largest and most respected bicycle manufacturers worldwide.