I have added Lobo Convention Special (1993) #1 to the list of parody references to Liefeld characters. The listing can be found on the A1 – Parodies and Meta References page.
On page 17 there is a small image of Bloodwulf (above a sign reading “POWDER ROOM”).
(There is also a reference to Rob himself.)
I have not seen this book listed as a Bloodwulf appearance/cameo anywhere else.
Extreme Excursus 