I just sold off my last pair of adults and this years hatchlings. I worked with them for about 5 years. I had a total of 5 adults / sub-adults at one time, Anerys and hets. What worked for me was slightly lower temps, 80 degrees during the day and a couple lower at night. Cooling / brumating temps in the high 40's to low 50's. Never less than 75 days and usually a full 90 days of cooling. Slightly different from my corns, kings, and hogs.
Keeping elaphe flavs is not real difficult. It can take a full 4 years to get up to size for breeding not the usual 3. The greatest problem I had was with egg binding. When I quit feeding them like other rats and corns, I quit losing them. I feed slightly heavier just before going in for cooling and right after coming out. I then cut back to one mouse, rat crawler, etc. every 7 days. Even with the males, I keep them lean.