declaring the setting:
[AutoCompleteSettings]
AutoComplete= enabled
SolrParams[]
SolrParams[facet]=true
SolrParams[facet.field]=ezf_sp_words

these settings will not show on the query sent to Solr.

to test:
1 - lauch solr from the terminal to see the solr output
2 - enable autocomplete
3 - write some letters in search box, check the query request on terminal that arrives to SOLR
4 - setup the SolrParams field with any setting
5 - clear .ini caches
6 - repeat the same query. the settings should be included in the request query that SOLR shows on terminal