Do we really need Solr commit as cronjob?

[Gao]

I am testing Solr FTS on dovecot. Read online that some suggested to run 
cronjob commit every minute, and optimize once a day.

I am using Solr 7.1.0 and I see some configurations:
In /etc/default/solr.in.sh:
#SOLR_OPTS="$SOLR_OPTS -Dsolr.autoSoftCommit.maxTime=3000"
#SOLR_OPTS="$SOLR_OPTS -Dsolr.autoCommit.maxTime=60000"

Also in solrconfig.xml:
     <autoCommit>
<maxTime>${solr.autoCommit.maxTime:15000}</maxTime>
       <openSearcher>false</openSearcher>
     </autoCommit>

    <autoSoftCommit>
<maxTime>${solr.autoSoftCommit.maxTime:-1}</maxTime>
     </autoSoftCommit>

So my question is do I still need run cronjob for commit?

Do I need uncomment these lines in the solr.in.sh? Does my 
solrconfig.xml overwrite the setting in solr.in.sh?

Thanks for help.