Another vote for it being a good idea, particular given hdr10+ content is out there and many tv’s support dv but not hdr10+.
I think this could get interesting in terms of trying to come up with a better way of converting hdr10+ to DV. From this comment the dovi_tool seems the to only set L1 data, not sure if this info is outdated though. The more interesting part in the link seems to be the comments about a bezier curve to adjust mapping and being unable to translate that directly.