Finally got around to designing and deploying boarding parties! There was an unarmed Precursor vessel stuck in one of my systems after I took out all their listening posts. It'd show up periodically on my display as it rotated through the orbiting sensor sweep. So I figured, "Aha! A perfectly safe target to try my hand at combat dropping marines!"
Trained four marine companies, built four combat dropship FACs with 14000km/s top speed (to increase chances of a successful intercept), and a FAC tender to hold them all, plus more comfortable quarters for the marines.
Shipped out the capture squadron (with a pack of destroyers on standby in case things went pear-shaped). FAC Tender had shrouded engines so i was able to close in nice and tight, park the tender, transfer the troops into their drop pods, and launch all four FACs.
Hostile caught sight of the incoming dropships at about 20k range, and tried to run at about 6200km/s. No problem catching him. Despite better than a 2:1 speed ratio, half the marines missed the target entirely and were incinerated in the engine flare. Two of the companies landed on the hull, but since the armor was unbreached, they had to deploy charges and burn their way in. No biggie, since it wasn't a firefight situation. They finally crack the hull, slip inside, and combat ensues. Combat sitrep in 120...90...60...30...
And then I discovered the hard way that I'd tried to board a Combat Transport. My combat ratio was 0.0008 >_<
I can only imagine the curbstomp battle that must have been.