The contra with the aspirational Phil and Royce bottom brackets is that at best they merely put off the day when they have to be replaced and cause extra expense because a different standard axle must be fitted, with at a minimum new cranks of that standard. Perhaps for a cyclist who rides a couple of thousand miles a year these bottom brackets will outlive him. But for a high-mile tourer -- perhaps even in hostile environments -- they just put the evil day off. Here's a workable-spec Royce on sale at SJS for only 180 quid incl VAT; the landed price for a Phil of comparable spec would be around there too:
https://www.sjscycles.co.uk/bottom-brackets/royce-titanium-bottom-bracket-with-73-mm-shell-red-all-weather-seals-and-stainless-royce-crank-bolts-110-mm My own instinctive advice to a high-miler keen to future proof his bike would be to lay in a stock of 73mm square taper bottom brackets, and not only to look at brands with big names.
SJS for instance carries a VP bottom bracket with suitable spec for about eighteen pounds.
https://www.sjscycles.co.uk/bottom-brackets/vp-bc73-107mm-bc13724t-unit-price-us304pc VP is a wonderful Taiwanese firm which makes hight quality cycle gear built around their very high quality bearings and I wouldn't be surprised if the UN55 was made by them for Shimano; I have their headset, with a pricey German brand name on it, and for years I've been recommending their VP 191 block pedals with sealed bearings; one pair of VP 191 was given to me by Trek when I complained about the quality of the expensive boutique pedals that came on an expensive prototype bike: that was twenty-odd years ago and those pedals, which were off their general manager's bike and so pre-loved when they came to me, are still on my daily bike, in perfectly smooth condition.
Another generally available bottom bracket I saw on the SJS site, the Stronglight JP400, which is a Czech-made bottom bracket of impeccable quality found with a lot of famous names on it, and fitted as OEM gear on upmarket European bikes. It's available with plastic, alloy or steel threaded cups (pro tip, as they say: get the one with the plastic cups, which is also the cheapest, to give your Rohloff a bit of protection by flexing as required --
https://www.sjscycles.co.uk/bottom-brackets/107-stronglight-jp400-plastic-cups-sealed-bearing-square-taper-bottom-bracket -- £15!). Some of the unbranded generic versions of this BB made in its millions are amazingly cheap.
SJS also has a Tange in your size; the Tange looks like a big bargain too.
Any of these is as good as a UN55.
I quote the SJS prices, which we know come with a possible hefty loading for you, because these bottom brackets are
in stock at SJS. I made a brisk tour of dealers I know to be reliable in France and Germany -- xxcycles.fr in France, and bike-components.de, roseversand.de, and starbike.de in Germany; all have anglophone sites available. I was looking for a cheaper carriage option within the EU, but discovered not a single square taper 73mm bottom bracket, which is why I suggest laying in a stock.
In the light of the stock situation with 73mm bottom brackets (a portent or a pandemic glitch?), the Royce and Phil options start to seem more attractive.