Bill Claff has published data for a1: https://www.photonstophotos.net/Charts/PDR.htm#Sony ILCE-1
It is good to see that a1 does not relinquish any DR to the a7r series, i.e., it should be able to replace both a9 and a7r bodies.
Sony a7rIV vs. a1
It is good to see that a1 does not relinquish any DR to the a7r series, i.e., it should be able to replace both a9 and a7r bodies.
Sony a7rIV vs. a1