You may not know this but the OP purchased a "new" inventory showroom vehicle that is actually a 2018 pre-raven model S.
Good catch! Thanks.
...much identical to my car, minus the smaller battery pack...
Sorry that I didn't notice that you also have a pre-Raven Model S and drove a pre-Raven loaner as a comparison.
In that case, I have no idea why the regen is more in your car and less on the loaner provided the settings are the same.