Is this for game balance reasons, or for dramatic tension reasons?
I'd say both, to a degree, although more the former than the latter.
One of the things I discovered with designing my current project was that making certain disadvantages into Plot Hooks -- personal obstacles that gave experience points
during the game when encountered, rather than upfront when taken -- worked better for some problems than for others: drawbacks like Nemesis, Secret, Ostracism and so on made good Plot Hooks because they were inherently story-related and had many different dramatic variations, but making Bad Sight or other physical impairments into Plot Hooks was ultimately just boring, because you can only lose your glasses so many times in a key encounter before it gets dull.
(The reverse of this might be called the "Kryptonite Problem": when your otherwise-unstoppable hero has
one major weakness, it shows up in the stories a
lot more often than the in-setting fluff suggests it should, because otherwise you have no drama for your hero.)
So perhaps here we have one of the major distinctions: If an impairment workaround is being used primarily for
game purposes, the primary tension is over whether the workaround will be
un-available in a given encounter. If it's being used primarily for
dramatic purposes, the primary tension is over the exceptional requirements imposed on the PC when the workaround
is available.