So basically there's nothing wrong with taking MCTs PWO and there may be some benefit, but they should not replace carbs at all in PWO meals.
As for the rest of the day, well... who knows? They don't seem to slow down digestion too much, so having some with a pre-workout meal may help keep you from burning glucose during your warm up, which should leave you with more energy to work hard with during the work out. A small amount is 20-30g, which works out to 180-270 calories worth, which should take you through a 20-30 minute warm up.
I personally have a fairly balanced fat to carb ratio when averaged out over a 1-2 week timespan, but I have days where I have almost no carbs and days where I have quite a few. It just depends on what I seem to need, and it works well. I stay lean and get strong, and that's what I like to do.