I consider that proper use of swearing only comes with old/older age, it is definitely then as the world seems to be out to get you/me that it is really needed!
Flare nut spanners really should be used when connecting up pipes like at the ABS block, nowadays, I always "crack" the bleed nipples using a deep hex socket, and if I feel the need, the same when giving them a final slight "nip up".
Really small bleed nipples worry me when I come across them, as said already they are keen to shear off.
An aside comment:- I bought a "re-manufactured by Pagid" Lucas/TRW rear RHS brake calliper for my wife's 2015 VW Polo as the original RHS had seized up, bought it via Halfords, it looked well re-manufactured ie back to original condition. So, I had the idea to catch the rear LHS before it started seizing due to moisture ingress, so bought another Pagid one from Halfords - this one, at some time in its life had ended up with a stripped bleed nipple thread, so the M10 hole had been opened up to M12/M13 and a threaded repair insert had been fitted, but its internal thread was M7 or M8 so I was ending up having one small bleed nipple on that car - in the end after a lot of huffing and puffing, I just handed it back to Halfords quoting "not re-manufactured back to original state" and added that I don't think that Pagid, or however Pagid uses to re-manufacture brake callipers are qualified to change any part of a safety related product. Halfords said that they couldn't guarantee that the next one they supplied me would be any better! Plan B is to, when the warmer weather turns up, remove the still okay rear LHS calliper, remove its piston and polish it and fit a new score seal and dust cover. So, thanks Pagid, you've forced me to actually service my own brake callipers to avoid them ending up seized - and I've even bought some new aluminium banjo bolt sealing washers - in case they are needed!