I'll be having my 2006MY SC MOT'd in the next week or so (my first FFRR MOT). Due to the complexities of these vehicles I'm just a little concerned that if the MOT tester isn't fully up to speed on them he might inadvertently cause some damage.

For instance, brake testing on the rollers which can ruin the diffs – that's the only one I know of, are there any potential pitfalls I need to be aware of? (I will be present and watching like a hawk  2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)

If you're worried then take it to an LR dealer. The MOT fee is fixed by the government and you can at least be sure that they know how to deal with the fattie. 2021 D350 Fifty Edition - Carpathian Grey
2017 4.4 SDV8 Autobiography (2021-2024) - Santorini Black
2012 4.4 TDV8 Westminster (2016-2021) - Santorini Black

My MOT man tests my brakes outside on the road with a handheld unit.... he only has one axle set of rollers in the workshop.

All 4 wheels would need to be on rollers.

Nothing special on mine other than that.... 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

Most MoT testing stations have to road test and use a Tapley meter for the brake testing on vehicles with permanent 4x4 like the FFRR.

This is because they are only fitted with single axle rollers and if used for a 4x4 it would drive itself off.