[RFD] How legal is it to delete dynamic tags?

[Matthew Fortune]

I have a bug report from Debian showing that the DT_MIPS_RLD_MAP_REL
tag (introduced on MIPS to support shared library debug with PIE)
can be corrupted by a program called chrpath.

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=818909#43

chrpath is designed to alter or remove DT_RPATH entries. Removal is
a problem when such an entry precedes DT_MIPS_RLD_MAP_REL as the
relative offset stored in DT_MIPS_RLD_MAP_REL then points to the
wrong address.

Firstly, to what extent is it OK to just delete a dynamic tag rather
than set it to DT_NULL?

Secondly was it a bad decision to create a slot-relative dynamic
tag? I.e. If I were to fix chrpath to know that DT_MIPS_RLD_MAP_REL
needs updating... are there likely to be more utilities out there
that fiddle with dynamic tags in this way?

Thanks for any insight you can offer.

Matthew