given existing problems with

fts_solr = ... use_libfts ...

i've rm'd it from dovecot config, and am moving all tokenization to solr config.

iiuc, in dovecot + solr context, that's correctly config'd in

solr/data/dovecot/conf/schema.xml

dovecot release ships with 'starter configs',

cp -af /usr/share/doc/dovecot/solr-config-7.7.0.xml /path/to/solr/data/dovecot/conf/solrconfig.xml
cp -af /usr/share/doc/dovecot/solr-schema-7.7.0.xml /path/to/solr/data/dovecot/conf/schema.xml

that^ schema.xml contains a limited solr.StandardTokenizerFactory config.

it can of course be extended; lots of generic solr config info available.

is there _documentation_, preferably a good example, of a dovecot-'friendly' solr config for non-"use_libfts" use case?

specifically, moving any/all of the libfts front-end tokenizers @

https://doc.dovecot.org/configuration_manual/fts/tokenization/#fts-tokenization
https://doc.dovecot.org/settings/plugin/fts-plugin/#plugin-fts-setting-fts-tokenizers

fully to a backend solr instance?

i suspect that solr config is fairly well insulated from dovecot's; what i'm not sure of is if dovecot's fts has specific requirements to get the backend-only tokenization working.