weird! dovecot running, but ignores /etc/dovecot/conf.d files

I have centos 7.4 installed ala perfect server (hi till!)
I installed roundcube and noticed I was getting FAILED TO SEARCH UID errors doing a search in a reasonably large mailbox.
looked at tail of /var/log/maillog and I see out-of-memory errors with recommendations to increase vsz_limit (it is 256MB).
well I edit /etc/dovecot/conf.d/10-master.conf (where vsz_limit lives) and increased the default_vsz_limit to 1024MB.
no difference! same error. and it says vsz_limit is still 256mb.
then I manually put vsz_lit into the service imap block. no change.
then I copied the service imap block (including vsz_limit) up into the dovecot.conf in /etc/dovecot.conf - and voila - it sees the extra memory and works.
I notice the dovecot.conf file has NO !include conf.d/*.conf line at all or anything like it. it is ignoring anything in conf.d
is this intentional? if not would it work without the include * line?
most odd.

also _ i see a reference elsewhere to a file missing from /etc/dovecot/conf.d - 99-fts.conf which turns on dovecot's full text search. suposed to speed up things. is it missing by design? and reason NOT to create this file in /etc/dovecot/conf.d?

 

ok might be good idea to point that out in perfect server! I had no idea they were not used - till I noticed no changes made any difference.
is there value to the fts (full text search) that is implemented in 99-fts.conf? that have value and should I try that out in dovecot.conf?

 

I'd prefer an upstream include for conf.d - maybe scan for enabled configs and disable them... but I don't like to check the master-config template or redo changes every update.