Insider Fares are on AA, AS, and DL when using pay with points in full at AMEXTravel.com.

AMEX Plat Travel agents can also sell AA Insider Fares on the phone for cash with a $39 booking fee per person.
Useful if short on points.
Unsure if same applies to AS, DL Insider Fares.

AA Insider Fares discount close to 10%. AS, DL about half that.

No reason now to put charge on personal plat instead of business plat when using pay with points.
There are no points earned for a full pay with points transaction now.
Never heard of a denial of 35% rebate if using personal plat.