The whole purpose of using plaster as a mold is something porous that can take the moisture content out of the latex and provide a high density end product that cures for sure. If you us any mold release you have blocked that way of curing. You then have no ability to tell how long it should sit to develop a certain thickness.
If something is popping off the surface as it cures, it is distorted as it sets. Maybe minor but it could just fall off if the mold is at a strange angle or you are doing slush casting and letting it cure out further once most of the latex has been removed.
Foam latex is using an oven to bake out the moisture and mold release is technically used so the foam does not bake onto the mold. Silicones and urethane castings as they chemically cure reach temperatures of 115 to 140 degrees and similar to baking so mold release is used there too.
Casting with latex has been done for more than 100 years now and you can use fish oil as a mold release or wale blubber if you wanted to. Neither one comes with a little instruction paragraph. Maybe a help me note from Captain Ahab.
The other reason to not use mold release is what ever was used is going to have to be nutralized or cleaned in order to paint over them. Or at least having something that will last and not nick easily. If you did a proper latex casting and the moisture went into the mold, you clean the mold and the end casting is very close to being ready to paint as it is bare and uncontaminated. This also applies for adding anything to the casting besides paint.
Getting only 15 or 25 pulls from a mold is what gives it some exclusive higher value. You can't be buying one of a couple thousand. Some detail might begin to become complicated with cleaning and demolding and so the every all design should be where detail is something added to the casting with each one being unique as an opportunity. Each unit becomes precious and numbered and if there are to be thousands, there is a master plug to remake more molds rather than rescultping over and over different versions.
This difference in quality is judging that something will be used on TV once for 2 minutes and you make 5 of them as back up or you have one mask that will be worn a couple years and see real mechanical fatique and scuffing or be on display for years. Mass produced 1000s of masks are $18, good quality are selling for $100 to $200. Mass produced ones with the wrong density start to dry out in 2 years. Old school masks have lasted 50 years and gone through restorations if they were important designs.
It actually doesn't take more time or care to provide better quality. Lots of people do things with a drill rather than get their hands in the plaster and such and end up with problems. Quick and dirty isn't necessarily bad. It is having the proper knowledge of with why products have been used in such a fashion and the history of why it is done in such a fashion. Anything that has the word acid in it is no longer archival, in other words it isn't going to last, something has been sacrificed. It might be fine for short term there it is, captured on video or film and throw it away, apply 3 a day shops.
For haunt applications, you are going to end up with some money invested, time invested and giving those pieces some history of being used in this or that haunt. They have an intrinsic value or the reputation of the artist at stake. So it is all more an application of how and where the end item is being used, or how significant the attachment to an item can be.
Another fabulous post from the U.S.Department of Wild Imaginings, now in spectaclar stereo, sponsored by the Adhesives and Sealants Council, suggesting ways to stick things together since the 1800s. Not fabulous in a gay way. Your results may vary. Illinois residents add 8% sales tax. These posts have been made by professional post makers, do not try this type of posting on your own without extensive training, lovely assistants and a trusty clown horn.