Hi afireinside :)
In this system cpev is very usefull. Its all about evap, it will work fine with small loads but when you're going to bench p4 you can see that not all amount of refrigerant stays in evap. It work like that because in high loads refrigerant evaporate a lot faster.
Gas bubbles crowd out most of liqiud refrigerant
(dont now if its correctly written but its hard to explain it in english :P ).
i belive what you are talking about is the leidenfrost effect
http://www.wiley.com/legacy/college/...rost_essay.pdf
its a very interesting effect that lets you put your bare hand into a pot of molten lead as explained and tried in the link above among other interesting aspects of this effect.
That liquid refrigerant cools cap tube and goes to compressor or stays in accumulator.
But if you do quite big slhx all liquid refrigerant will be used for subcooling and when you're using cpev you can adjust that evap overflooding to do some nice temps for u. With powerfull compresor you can condense high pressure gas this way, just give some liquid refrigerant to slhx.
It works almost like a watercooler because only small part of refrigerant evaporate in evap. Subcooling is so high that there is only few degrees difference between liquid going to cpev and going from it.
Sorry its really hard to explain it, maybe i'll paint it later :)