Writing is going to use master and subdocuments, be style-based, one template for all document components, custom styles maintenance on template level, set of styles to maturate along with writing.
Has following approach any major issues?
Look for .ott file named
Default, do the search in user home. LO was in use in the past that machine. If one gets found in a sub-directory yet sounding as owned by LibreOffice make a duplicate, move duplicate to user folder. Rename it according to local needs then register it with Writer. Copy in user folder gets removed, backups are made on folder which is added to Options… > LibreOffice > Paths. Do not set it as default template, anyhow use only custom template when master or any sub-document gets created: menu File > New… > Templates… > select custom template.