I hear what you're saying, but im on a number of Emtb forums, and those type of problems, especially affecting the motor is just not something i hear anything about. On here, the main problems people report seems to be with the hub motors, the wiring, the controller(as you say) battery etc. I dont know if its down to the costs, obviously the bosch/Yamaha/etc systems do suffer problems at times, but tbh those probs seem related to water ingress from the nature of their use, going through streams etc.
Because of this i would suspect that the mid drive systems are certainly robust, especially given the abuse they go through, which cannot really be compared to the plodding steady commuter types the hub motors seem to favour.
Its because of this that i would lean towards there being less of a problem. A pre wired system i have read today in EMTB forums, where the customer watched them fit an expensive(£400) Lupine lamp to a 2020 Scott Emtb, that they just twisted the wires from the lamp onto the wires from the pre wired system, so i would think from that that the procedure of connecting these lights is less fraught with potential problems, and more akin to a 'plug and play' type of set up.
I think the only problem i would have to watch out for is the one you mentioned earlier about the ampage for the light 1, 1.5 or 2a. But with the light being 1000 lumen, its going to be a case of setting it at its lowest (1a) and seeing how that goes. I admit to having issues there in that I cant find exactly what he ampage of the light i have is, only its lumen rating. I think i'll probably have to email Exposure to find out. Apparently like Hope, they are amongst the best mtb component companies for customer service.
I think also an email to Scott, possibly in way of chastisement as to their lack of fitting instructions for fitting lamps to their bikes. They make a big play about it being 'pre wired' but the info seems to stop there and theres no instructional vids that would help.
Perhaps they are reckoning that the owner would be employing a shop to do it, but perhaps they havent taken into account what is involved* .
* Far as i can see to open the cover, you need to remove a lower motor guard(damn these mtb's needing protection) to access the screws that hold the motor cover on. And im going with a generousness thoughts on the matter. It might actually need the motor to drop down just to access the cover screws- A job ive been avoiding.
If thats the case then that is really dumb and it would obviously cost the customer more.
The bike shop i got it from i think is really ripping folk off asking 50/hour. Theres another mechanic i use, possibly one of the most qualified in the country, has the full range of cytech certifications, and was the Olympic mechanic for Shimano a couple of years ago. He's charging about £25/hour. So having the ebike shop asking 50, is just taking the proverbial. Which makes me lean more heavily towards doing the work myself(plus the super qualified chap lends me his tools occasionally, which is certainly handy.
So I'll take on what you've all said and try to be careful, but also research a lot more as to what exactly the voltages/amps etc etc actually are before making a goo of it. I've very practical in these things been building bikes for 25 years, i service sus forks, rear shocks, hydraulic systems as well as everything else, so i reckon a light shouldnt present too much of a challenge, especially with the info you guys have supplied.