Rotor and hub compatibly issues

I'd blame this one on Hope tbh, like you say you've gone years without ever having a problem, now you're having it with one specific hub. I can't find the actual ISO for 6 bolt discs, I doubt it's a specified size, but anyone cutting into that clearance on their hubs is pretty much asking for trouble imo.

Just checked with my Hope pro 5 and it's the same issue as the pro 4, seeing as the rotor only came out this year or late last year I'd say it's a TRP oversight for not checking against one of the most popular brands out there, there's plenty Hope hubs out there and not just in the UK, unless someone has found another rotor that doesn't fit Hope hubs I'm still blaming TRP,  I think Hope would've addressed any problem years ago and definitely wouldn't have continued it on their latest offerings. Just my humble opinion but I'm a Hope lover so could be a bit biased.

I used to bike commute a bit in the 2010s, then spent a couple of years driving around the country to various sites and barely touched a bike. Got a job 7 miles away just as covid landed - by the time we could go back to the office I hadn't ridden regularly in three or four years, and the return leg of that 7 mile commute was enough of a drag that I just took the bus. Got an ebike a couple of years ago and haven't bussed it in since! I've started keeping it power off on the way in, then using a bit of assist to help on the way home. I have no idea why I told you all that. 🙂 

However, we (Mrs Pondo e-bike commutes too) kept our cheap old Amish (such a great term 🙂 ) hybrids as emergency backup and also to take on holiday, so the e-bikes don't get salt- and sand-encrusted, and aren't subject to long days on the bike rack. Took them out around Oxford this weekend, and they were GREAT! Can't beat the e-bikes for commuting, big loads or hills, but that doesn't mean there isn't a place for their analogue predecessors. 🙂 

they're catching the raised shoulder of the hub shell that helps center the rotor during installation.

It doesn't, well not unless they happen to have the same diameter which it seems isn't controlled in the standard if TRP have come out with a disk that doesn't match it.  Although having said that I definitely have some wheels where it sits together nicely, maybe that's just a hope thing.

Depending on the clearance you have in the fork and caliper (don't forget the heads of the 6 bolts too) you could put a ~1mm spacer behind the disk, hope make one.

Or just file down the disk like you planned, to center it you're supposed to put the bolts in until the disk is in place but not yet snug, then twist the disk anti clockwise and tighten the bolts.  That way the disk holes end up centered radially (but offset circumferentially by ~0.5mm which doesn't matter). 

I've got a Hope 220mm floating rotor in the spares box I could sell you if you want to send the TRP one back.

• To be honest I just made up that description of the shoulder because I couldn't think of anything else to describe it, centering seemed reasonable, maybe it just helps keep the rotor there or thereabouts until you put the first bolt in, I didn't really give it that much thought, I've got a few 220mm rotors so it's not urgent, thanks anyway, I'm just gonna file it or get the Dremel out when I've got time to do it nice and even, I don't wanna rush it,  I only bought it on a whim, I thought the little holes look cool, apparently they help with heat management and improve deceleration by 10%, I'm interested to see if I can tell the difference or if it's just marketing nonsense.