ACES is already the simplest way to start from the same basic grade and deliver SDR and HDR versions with only a trim pass needed for whichever is the secondary version. The tone-mapping (contrast curve) is already split between the RRT and the ODT, with much less shadow and highlight compression happening in the HDR ODTs, varying with the maximum white level of a particular ODT (there are 1000, 2000 and 4000 nit variants of the ST2084 ODT).
Whether the roll-off in the current SDR ODTs is too strong is the subject of debate. The “Retrospective and Enhancements” document @Thomas_Mansencal refers to above suggests that the default rendering transform be made more neutral, with the “look” aspect being moved to a default LMT, which is optional. I think this sounds like what you want too.