I have a bride that asked for the grooms cake to be carrot cake. I told her I am not comfortable using cream cheese icing because it will have to sit out for several hours. She asked if just the filling could be cream cheese. I haven't emailed her back yet, I was trying to find out if I could use the LorAnn cheesecake flavor to get the cream cheese flavor and it be safe for it to set out. The site I went to for the cheesecake flavor said it was good for chocolate so I didn't know if they work for buttercream?
Yes you are good with plan b there.
Also there are sleeve 'cream cheese' fillings that are also safe at room temperature. You could doctor one with the other too.
You're a wise decorator to use your head on this.
Their cheesecake flavor is yummy too, I used it to flavor MMF and it worked great. It's a pretty intense flavor.