My favorie UG uses ethyl oleate as oil, along with BA/BB. It doesn't crash, even at concentrations of test enan at 350mg/ml. The e.o. is smooth, even waterlike. Internet lab reports on concentration, plus my own bloodwork prove it's all legit.
Their range of products includes test prop, enan, cyp; tren ac, enan; boldenone und, masteron, deca, drive, sust, and liquid D-bol, which is the only one that sometimes crashes.
So by all means it can be done. I do not know if they add anything else besides the BA/BB.