Exim and Lookups

Find that in Exim

Lookups: lsearch wildlsearch nwildlsearch iplsearch dbm dbmnz

has Mysql lookups obviously missing.
Questions that arise are:

(1) Why is any Mysql support is invariably always excluded? This would obviously be answered by cPanel staff/developers.

(2) Has anyone tried having it built into exim and use the same on cPanel servers?

Found similar Mysql support missing from default cpPanel's pure-ftpd but could get that going by rebuilding the src.rpm

TIA
Anup