> is it normal, that cmp 4.03a still reports 238 v5 converted CHDs as unneeded > (incorrect SHA1) for u3?
That is correct since a lot of the v4 CHDs have obsolete metadata and by converting them the metadata and so the SHA1 changed. Most likely these need to get redumped as well since they are lacking data the old metadata format did not support yet.
So far only the konamigv CHDs have been updated in the source, but they are also flagged as BAD_DUMP now.
Because of the GDI and LD CHD issues and potential future compression optimizations I would not convert anything right now. Wait at least until 0.146.