This question is probably better suited for the suspension forum, however the 38 adds quite a bit of weight and generally isn't needed in a 150mm travel application (not sure you can even get it in a 150mm travel). It also has a terrible A2C dimension.
I know that the SL e-bike weighs more than a mountain bike but it's not much more. So are you a large strong aggressive rider, or more average?
I'm 180# (on a bike though, not an e-bike) and do some decent jumps and drops and don't feel let down at all by a 35-36 fork set at 150mm.
A couple of tips:
1) The 34 on the SL was a concession for weight and should be swapped for something else for a larger/ aggressive rider. But it's appropriate for any non-Pro rider under 140#s or just a casual trail rider who is larger.
2) The Yari/ Lyric are both much more rigid than the Fox 36. My favorite option currently is the Manitou and at 37mm it's the most rigid of these options and the weight is very good.
3) I added a solid OneUp front axle and it felt like it made the front end more rigid on my Yari.
I have the 38 (and a 36, and Lyrik) and it is the best fork on the market. Have experience with the Zeb and it is a solid runner up. The RockShox forks tend to be more supple, but get overwhelmed in fast high speed chunk. Fox is the opposite, not quite as plush but very controlled when you are bashing through stuff.