Not possible to exclude "mountpoints" from sitemap using "excludedDoktypes"
It seems impossible to exclude "mountpoints" (doktype=7) from sitemap generation:
plugin.tx_seo.config.xmlSitemap.sitemaps.pages.config.excludedDoktypes = 3, 4, 6, 7, 199, 254, 255
The mounted pages are still included (for both "mount_pid_ol=0" and "mount_pid_ol=1"). In my case pages from a different site (domain) are mounted, don't know if this matters...
In addition (but maybe this is a desired behaviour because of seo aspects), the mounted pages are prefixed with the foreign domain (site) in sitemap, although in frontend all mounted pages are below the current domain (site).