Rushed to get confirmation of my initial impressions of the Vityas on the 035. Apologies for some blurry pics.
here is the upper handguard on the Cyma:

fits right in with a teeny ween bit of shaving on the front end.
here is a comparison of the length of the two lower handguards:

almost the same length. maybe a few mms difference if you are being OC as you can see from this pic:

and from this top view of the lower handguards:

the biggest difference is in the receiver tangs as can be seen in this view:

the front end of the lower handguard is a bit loose in the locking retainer but that is easily remedied with some foam or epoxy. the receiver tangs will need some cutting to fit and, should you prefer retaining the spring tensioner of the original, that would take some doing. not much though.
the fn-style grip fits on the cyma much better than it does on the Kalash. as expected, the grip tabs are different:

but that is not a big deal. i imagine cutting the tabs alone will give a good enough fit since there is the grip bottom screw to hold the grip firmly. fitted like a glove when i tried it last night -- much better than the stock cyma which is a bit loose. that is due, IMHO, to the very similar trigger slot cuts in the fn style grip:

the fn-style grip, which, btw, is what is in the RS and Inokatsu Vityaz, did fit nicely during the initial try without any alteration at all.
overall, it is my personal opinion that
IT IS NOT A BIG DISAPPOINTMENT. it can be that if you expect a drop in plug-and-play add on. but if you're the type who wants an effortless dress up, IMHO, don't do ACM. go high end. pay big bucks and, even then you may still have to sweat a bit and spread on a lot of elbow grease.

there is, of course, the possibility that final fit up may require more work than i've projected so far. we will see.
completing the makeover may take awhile (

there's quite a pile of pending projects on my worktable ) but will make sure to update with the a final fit up (one without the planned epoxy strengthening and some other cosmetic preferences) posting in this thread.
the final makeover pics will be posted in a separate projects thread. am thinking that will make it easier to find for other komrads.
thanks for looking.