Spalerosophis are indeed mildly venomous, but generally considered harmless to people.
Spalerosophis are opisthoglyphous, that is to say they have enlarged, groves fangs located at the back of the jaw, and these fangs are connected to a Duvernoy’s gland, which is the gland that produces venom in Colubrids. I linked a few papers below, the first two are studies performed on the toxicity of venomous Colubrids, both include
S. diadema. The third paper investigates morphological features of
Spalerosophis, including dention. I haven't been able to find much information on the effects of
Spalerosophis venom on humans. Since this is a bit of an unknown I would suggest caution when handling them, particularly to avoid feeding response bites from captive specimens, but I wouldn't worry too much about it. The delivery method is poor, and the yield low, so the odds of a serious envenomation is very low, as long as you don't allow the animal to chew on you.
Biochemistry and Pharmacology of Colubrid Snake Venoms (Mackessy, 2002)
Properties of Duvernoy’s Secretions from Opisthoglyphous and Aglyphous Colubrid Snakes (Einstein & Kardong, 1994)
Relationships of the snake genera Pythonodipsas Günther and Spalerosophis Jan (Reptilia, Colubridae) (Schätti & McCarthy, 1987)