the way focus production works is not entirely clear to me, but it definitely doesn't cause you to "allocate all of a planets production points to either military, social or research".
setting your slider to 100% social and setting focus on research does allow some research to be generated, but it's very inefficient.
For DL and DA, focus takes 25% of A and B and diverts it to C. For instance, if I have military/social/research at 50/50/0 spending, 200 industrial infrastructure on the planet (ignoring any bonuses, racial or planetary, for simplicity's sake, as only the base value is diverted), I'd have 100 funded military and 100 funded social. So when I focus on research, 25 comes from military, 25 comes from social, and they both go to research-giving me 50 before any bonuses.
In TA, focus's efficiency is reduced to 80% of its former self; that is, while 25% is still lost from what is being diverted, only 20% of the whole arrives-in the example above, giving us 2x20 or 40 research instead of 50.
Additionally, when focusing between social and military, or vice versa, 50% is diverted (rather than 25%)-and I believe that this is still 50% in TA, but to be honest I haven't looked at it in quite some time.
Finally, some important points:
-Only base production counts. If I have a planet with 5 industrial sectors, a quantum power plant, a manufacturing capital, with a 100% military bonus (for instance) from customization points, techs, and Industrialist party, I'll get the same amount out of focusing on research as I would with a planet with only 5 industrial sectors, even without any racial bonuses.*
-However, production that arrives via focus does in fact get the bonus of the type that it arrives at-so our 50 research above gets multiplied by the research bonus (which is itself multiplied by difficulty in a way-that is, difficulties higher than Tough give an artificial, hidden bonus to the player's research-topping out at 2.64x as much from a research bonus on Suicidal-that is, a normal player with 100 research x 50% would have base+50=150, whereas you would have base+100 x (50*2.64) = 232.
-Last but certainly not least, as like virtually everything else in this game, these values are all truncated. So if I have 3.9 funded (which will only net you 3 total), none of it will be transferred via focus-but some will still be lost. In particular, this means it's rather useless without much infrastructure present-especially so in TA, where the transferred points are further reduced.