From studying video, I believe the Hearty Victuals will spawn with traps (as opposed to traps only) if Miser's HP is below roughly 40% when the traps are set to spawn. I haven't seen a video from you guys, but if this were true, it would imply that you guys get Miser to ~40% or better within the first 60 seconds since the traps spawn 1 minute after engaging Miser. If you slow damage down to only get it to say ~50% HP after 60 seconds, you'll get the normal non-Hearty Victual configuration.