Hi Erik,
Great questions.
- Is it necessary to have an explicit conversion thorn? Couldn't these routines be simply part of IllinoisGRMHD? For example, McLachlan uses its own variable, and contains its own routines to convert from/to ADMBase.
IllinoisGRMHD is designed to maximize user-friendliness, and to this end one of my goals is to minimize the amount of source code inside IllinoisGRMHD that is not directly related to GRMHD evolution. Thus if possible, I would prefer not incorporating functionality from these thorns into IllinoisGRMHD.