This may be much more than you want to know, but Len Poli has a great site devoted to sausage here:
Briefly, you need to be careful smoking to make sure the meat isn't in the danger zone too long. Does he use a cure in the sausages? That too is a factor in how you handle and cook them.
Jim - Another transplanted Texan
Former KCBS CBJ
Large and Medium Big Green Eggs , Black 18.5" WSM, Blue Weber Performer - Stainless, Green Weber OTG Kettle , Brinkmann SnP Pro, and a Stainless UDS. One retired Portable Kitchen grill.
Red Thermapen, Maverick ET-732, EdgePro Apex Sharpener.
Avatar is the original 1951 Weber Kettle