From what I understand, Snowbound Blood is a prequel to VE in the vein of Friendsim and Thaumatrope is another prequel that I think takes place after SB.
I'm leaning toward going chronological (SB -> Thaumatrope -> VE) but for many stories it's best to go publication order so I want to make sure I'm not making a horrible mistake if I read SB before VE.
For reference, I would consider it perfectly reasonable to play Friendsim before reading Homestuck - it changes the order in which you learn certain information, but nothing that really spoils important revelations. Technically it's the canonical order in which the MSPA reader experiences things.