@EBRQuest:
The MTB world (not necessarily e-MTB, just mountain-biking realm) has own rules how a mountain bike should be designed. Since the Specialized Stumpjumper (1981), the bike industry was learning about the mountain-biking needs and developed the technology to the paramount level, with these classes of e-MTB: Cross-Country, Trail, Enduro, Downhill, All-Mountain. Every smallest detail of a modern MTB was thoroughly studied. The technology progress in MTB affected other bike classes. e-MTB is even more complicated, and the first real e-MTB, Specialized Turbo Levo was only released in 2015, with major improvements in following years, to come to Turbo Levo SL, super-lightweight, low-power, low-torque e-MTB that was met with applause. Because mountain-biking is a separate world with own rules.
To make a long story short: No serious e-MTB brand makes an IGH, Gates belt bike because these
do not belong there. You might say "and R&M Mountain?" No. It is like you were looking for an ATV and chose a SUV instead. The R&M never was and never will be an e-MTB.
You said you were underwhelmed with low torque of Bosch and Yamaha mid-drives. You should add to it Shimano, Brose/Specialized and Mahle/Specialized motors. All of them are up to 90 Nm, with the Specialized 1.1/Mahle one used in SL e-bikes sporting only 35 Nm! Why? Because you don't need more in an e-MTB. First of all, e-MTB is equipped with a very small chain-ring (32, 34 or 36 teeth), and the large cogs in the cassette are very large, for instance 51 teeth. The gear ratio is well below 1 there, meaning the motor torque is amplified at the rear wheel. For example, SyncDrive Pro (Yamaha PW-X2) offers 85 Nm max but it is 120 Nm at the rear wheel in the granny gear of Giant Trance E+ 2 Pro. The peak motor power of 520 W, full torque when you have just touched the pedal make the Giant ebike do a wheelie! Try this with an R&M.
I can guarantee that a Bosch, Yamaha, Shimano, Brose mid-drive e-MTB will climb any hill. You don't need a kilowatt or 120-160 Nm for that. You need an e-MTB.
Next thing is the bike weight. An e-MTB has to be possibly light-weight. e-MTB motors are lightweight, and batteries are possibly lightweight, too. There are many factors for that I don't want to elaborate on now. It is sufficient to say the Specialized Turbo Levo SL is almost as lightweight as a pedal-only MTB. The battery is small. The motor is underpowered and not torquey. Yet that e-bike is praised because it is as natural to ride on single-track as a mechanical MTB, offering the necessary assistance the unpowered bike doesn't have.
Mountain biking is not about power or torque: It is about riding technique. Please see several videos on Electric Mountain Bike Network channel, for example this one:
I apologise for this lengthy and direct post. Your thread title reads "Help finding FS MTB bike". If that would be "Help finding FS bike" I would even not say a word. Yet you asked to help finding an MTB. The bottom line is: No e-MTB from a respected brand (and there are many) makes a mountain e-bike with IGH/Gates belt.
You might ask your question in this thread, and then a real expert would tell you why.
Bring all your ideas here for mountain bike options for 2020 - now 2023 We had a lot of great discussion on bikes and models in Lenny's 50% off thread but some members complained about the thread content being relevant. So here's a thread to discuss all the options and bike styles, what you...
electricbikereview.com
Ride on!