Having gone through some of the UAVHUB A2 CofC modules the CAA have now classed drones by the Take Off Mass and not the MTOM, so a Mavic Mini weighing 249g is class A1, but as soon as you put the prop guards or anything else on it will weigh more than 250g and so becomes a class A2 drone.
I have a Mavic 2 Pro which weighs 907g out of the box, so that is its Take Off Mass as long as you don’t put anything else on it, I have been trying to find its permissible MTOM for if you add leg extensions, cree LEDs, launching handle, and any other payloads you might want to add. I have not been able to find it, so does anyone know?
950g. I don’t know where I found it but thats what’s in my ops manual.
The CAA classify legacy drones only by “flying weight”, that’s the term in CAP722 so best to stick with it.
“Flying weight” as a concept has no legal status, it’s just something the CAA made up in the guidance because the actual regulations don’t really make sense for legacy drones otherwise.
The MTOM will only be relevant for future “C-class” drones, so there’s no point looking it up for a legacy drone. Manufacturers don’t generally state it, as you’ve found. They will have to state it when they sell a C-class drone.
The Mavic Mini weighing 249g is a “legacy drone <250g flying weight” in CAA-speak, which can be flown in Open subcategory A1 forever (or until the regulations next change).
Add any accessories (still <500g) and it is an “A1 transitional drone” flying in sub-category A1 until the end of 2022 (with A2 CofC), and after that a “legacy drone >=250g flying weight” flying only in A3. (It doesn’t matter what its theoretical MTOM is because it’s a legacy drone.)
The Mavic 2 Pro weighing 907g is an “A2 transitional drone” flying in sub-category A2 until the end of 2022 (with A2 CofC), and after that a “legacy drone >=250g flying weight” flying only in A3. It doesn’t really matter what accessories you add unless you tie a brick underneath and take it over the 2kg boundary for A2 transitional.
Short version: there’s no point paying any attention at all to MTOM for legacy drones. “Flying weight” is the only thing that matters for these.
“MTOM” - who ever came up with something that can be equally interpreted as Minimum or Maximum … Take Off Mass.