Don't worry about the wear on the brake pads, you will never use them with the KERS doing all the braking
This is very true, although I do suspect that the pads and disc's are still likely to get replaced before the friction material has reached anywhere near the wear limits, due to the lack of normal friction braking, due to the strong effects of Regen braking.
I believe both dealers and MOT testers will focus right in on the condition of the brake disc's and request replacing them as a very lucrative occupation at the time of service / inspection.
Brake servicing is already featured / seen as common place on many EV's already.
Nissan Leaf and Tesla models being just two of them.
Friction pads first become seized in the calliper body due to the weather conditions and road salt etc.
Corrosion and the lack of lubrication at the point of assembly, causing uneven and premature wear, due to brake pad dragging on the disc.
Pad or pads dragging on the disc then creates excess heat, which then cause the steel brake disc to warp and then in turn produces vibrations through the foot brake and steering wheel when heavy braking from a high speed is required.
Your totally correct, you will never wear out the pads, but is likely you will require them replacing prematurely due to the above reasons I have mentioned above.
Can this be largely avoid, of course.
Removing the pads on an biannual basis and then cleaning and applying the correct lubricate to the contact points, will very likely THEN out last the car for sure !.
If you are able to conduct this type of work yourself, then there is no cost associated to this type of preventative maintenance and is totally worth the effort.
But having the dealer carry out this work two or three times, could work out as expensive as just replacing the parts as and when they are needed I guess ???.