because I'm a biased axis fanboy right....
Well given you've been crying 'BOFORS OP' this whole time despite knowing nothing about Brits as a faction -i.e. self repair aka 'Stand fast' is doctrinal from Royal Engineers regiment alone, I'd recommend you keep your mouth shut on any and all balance issues given you're only looking at it from one side.
How about you put aside you schrek blobs and 'defend ze fatherland from allies fanbois!' forum warrior attitude for one minute, play some f**king games as allies then come back and tell us how balanced certain units really are.
Jesus, I thought Katitof was an intolerable allied zealot at times, but you make him look like a moderate (that said, he's been pretty mild as of late).
Gopher. Play UKF. Build Bofors for your self and see how 'invincible' it truly is.
/rant
As for this whole thread, it's a partly down to a terribly campy, narrow map that favours static play and makes any indirect fire and area denial all that more potent. I hate to sound cliche'd but the rest is L2P issues.
This happened because it was placed behind a shotblocker
So why are you not throwing incendiary grenades over said shot blocker for free damage?
As for double LeIGs - the only way you could have failed to kill it was by switching targets. Constant bombardment from 2 mortars or ISGs will wreck any brit emplacement after enough time, all the brace and stand fast in the world will do is buy it a bit longer, as any sappers attempting to repair will inevitably get rekt along the way.
Flame weapons deal 30% bonus damage to structures, so stuff like smoke + volks nades/flame HT work wonders, even killing it through brace. Hell, you can even kill it with a volks blob provided you don't get suppressed on the way in - 3-4 schreks will seriously threaten a bofors and the moment it braces it's not fighting back, all you have to do is wait ~25s then throw an incendiary grenade or two.
Like many have said, best option is to force it to brace then hit it hard when the ability expires 30s later.