What about starches like tapioca, potato, and arrowroot, for incorporating with flours like almond flour, coconut flour, or brown rice flour? Are these ok?

Yes, they are okay post program. Actually almond and coconut flour are fully allowed on the program. Unmodified raw white potato starch by Bob’s Red Mill is considered to be a resistant starch and therefore low-aggravating to SIBO/FODMAPS, supportive to the adrenals, and is allowed on this program. Tapioca should be limited on this program, but arrowroot is fine in moderation.