Mostly connections are up for days or weeks at a time with occasional bursts of terminations then re-connections a minute or so later as I load new code and have to debug it. I’ve seen rate limits before when I’ve been in a particularly churning debug cycle (especially if it crashes without closing streams down properly) but they went away after half an hour or so, this one seems to have stuck!
I’m not sure if it’s an IP ban as I can successfully use either stream or filter now, just not both at once (though I haven’t tried both at once for a few days).
Two connections would suit me fine, so is a “small number” one or two? I understand the need to be vague on limits at times to prevent gaming but surely “one or two” could be pinned down? 
The use case of one connection per type of public stream can’t be that unique can it? Especially in the realm of art bots where “observing the twitter zeitgeist” via the sample stream at the same time as using filter for command input seems, to me, to be not that unreasonable.
Anyway I fully understand that this is a marvelous service provided for free and I have no right to demand anything, thanks for letting me do what I’ve done so far!
Cheers,
Robin.