i am sure we'll all run with reverse shield polarity if we can, it is simply the BEST ENG power there is, effectively it is god mode for 15 seconds.
now the question is, if one look at power description in the power window, it actually dont say what skill improves this power, either is there is magnitude or duration for which it can be improved on. the magnitude is always 100% damage converted to shield (at least i think so, otherwise there is no easy way to tell); and the duration is simply linked to the rank of the power. however the skill windows seem to say that the skill shield performance (t4 skill) improves this power. i am not sure what is right?
if you are not running ENG captain, there is no reason to take this skill, so if it is possible i would rather skilp it and save these skill points for something else.
There are 3 skills that boost RSP like every other skill
BUT: You don't boost duration or cooldown, you boost the amount of energy your shield gets back per hit. So the use is questionable. You will still be nearly invulnerable without any points in shield-skills, but your shield will fill itself up more slowly.
i can only have a educated guess of what these 3 skill are, as they are not listed in the power windows.
like i said... there is no easy way to test how much of the damage is converted to shield. unless you can proof what you say, i'll just treat you view as a guess.
Starship Engineering Training
Starship Shield Maintenance
Starship Shield Performance
And I don't know how I shall prove you this, I don't have a video showing the different effects. But if you want you can raise your mousepointer to "Search" and look for other interesting RSP topics with a lot of people stating the same thing.
there is exactly 13 post about them of which only about half are of any use.
all of them dont have anything definitive to say about RSP. like i said, i assume the percentage damage converted to shield is the same, and there is no easy way to test this. everyone had assumed that the bonus to shield increase with skills but since there is no tooltip or power skill description to compare. no one knows, and i can only take this as a guess.
since the power info window dont actually say what skill boost RSP, i can only have an educated guess at what these skill are. keeping in mind that the some skills in the skills windows do have the wrong description, for example, "mask energy signature" have different skills (in completely different part of the skill tree) if you either look at the power window or the skill window.
Shield performance is worthy of being put points in for the simple reason that it boosts your shield power, no matter what setting you're using. It's hard to tell for me since I've got a frickin lot of stacking bonuses to power, but I think you can get AT LEAST a +5 shield power bonus from shield performance. +5 means a 20% bonus to the base recharge of the shields you're using.
EDIT: To give you raw numbers: with max warp core engineering, shield efficiency, shield performance, on a cruiser and with the efficient impulse engines mk IV, with shield power setting at 50 I have an effective shield power of 76. (oh, warp core theorist character buff as well, but you should have taken that anyway )