im pretty sure flags like cube, dome, scene, cylinder have to be set during definition only, not changable during runtime.

of course i've yet to run into a situation so far where i needed to change them.
I've only used ent_createlayer like 2 times and then found it not worht the hassle ( at least untill c-lite) as its easier to figure out max number of sky definitions you need visible at any given time on screen and define that many (if you have your project propoerly planned out). then change the alterable values as needed.

i.e.
define 1 skycube then chnage teh type= value for differnt images vs maming 1 defien for each image
define 8 sky model entities and morph the models as needed