Question for the Lurkers. Is it now possible to use Chase Free Night certificates (or those from AMEX post 8/18) at SPG hotels? If so, how? If not, when?

I want to use two of these at Le Meridien Stuttgart at the beginning of October. I made the reservation using points, but am hoping to substitute the Chase certificates.

I wrote email to support and got a reply from someone on the SPG side telling me to call. I tried, but ran out of time after waiting on hold for an hour.

BTW, marriott.com clearly lists Le Meridien Stuttgart as "participating" in regards to the free night certificates. https://points-redemption.marriott.c...rriott-rewards But the process it says to use to book it doesn't work for SPG properties.

Thanks in advance,