Why banjo fittings?

I haven’t ever had Hope brakes but when I first read your post I was confused, I was thinking a banjo fitting surely allows for more flexibility over the hose angle so should be better than a straight out fitting. Then I looked at a photo of one. Why they decided to put it on the top of the caliper rather than the side I do not understand, there’d be very little reason to need to adjust the angle in the direction that fitting allows so they might as well not have bothered.

I've often changed Hope fitting from one to the other to get a better hose path. Generally with post mounts, a banjo is fine. However, if the hose run along the same frame member as the mounts are on, it's a problem. Last one I changed was on my Vanquish frame. Post mounts on the chain stay and cable running along the chain stay. That needed an inline fitting

I guess flat mount fitting are normally closer to the frame member, hence inline.

The banjo orientation is a missed opportunity though. Could have offered all the adjustments you needed.

Once upon a time, the banjo bolt had the same thread as the bleed nipple and they could be swapped over. That was occasionally useful but I'm thinking back to the days of two piece calipers.

Totally agree; the banjo needs to be running parallel with the bike, not across it.

It would help a bit if Hope offered replacement banjos with different angles... ie., not just flat ones.

It might just be what they've always done. Mono M4 callipers had banjos but they ran parallel unlike the current E4 callipers. Older X2s were the same too.

On Hope brakes – why is it always banjo fittings at the calliper for MTB brakes, but inline fittings for the RX?  The Banjos suck.  They always end up with really daft cable angles and a difficult bleed especially when the rear brake is inside the triangle!  Why?

Most modern MTBs mount the caliper to the seat stay but then route the hose along the chainstay, so the hose needs to head down then along. RX are generally mounted the the chainstay and stay on/in it like would have been common on a lot of older bikes when Hardtails were dominant - in that case on the seat stay mind.

We often change out the fittings on bikes coming through our workshop - people are paying big bucks for Tech 4 fitting on their new 10k ebikes and getting some pretty shoddy work for the sake of a £1 hose fitting.

You can use straight fittings with hope as well. ( the same as at the lever end)  Between the two you get a whole range of angles possible.  I have a straight fitting on the rear of my shand for this very reason
Banjos give a better run at the front and the ability to adjust angle means that you get a very nice hose run

This bit ( the metal piece)  remove banjo from the hose and replace with this

With the older calipers I would always alter the angle of the banjo to get better/neater routing, especially on the fork but now it's kinda pointless to adjust it. In some cases I've not been able to use the last hose mount clip on the stay without putting a tight bend in the hose.

This is the part you need to convert a 5mm ( modern) hose to straight rather than banjo fittings

https://www.sjscycles.co.uk/brakes/hope-straight-connector-complete-5mm-black-hbspc33/