Hi @gurumance
WP Multilang do not support different slug for each language in base version.
Will it support in near future, or did you tried to contact https://wordpress.org/plugins/qtranslate-slug/ creators to see if they can integrate q-translate slug with your plugin, i noticed someone mentioned that migration to wpmultilang from q-translate x is possible. But for me and many others migrating w/out slugs is impossible.
This functionality will be available in paid version of WP Multilang. This is now in development.
Well i have to wait and see 🙂
Key points for most of the people that use qtx and qts is migration of slugs easy migration Yoast seo xml sitemap.
http://www.lachambredessecrets.com/i18n-index-sitemap.xml
http://www.lachambredessecrets.com/fr/i18n-index-sitemap.xml
http://www.lachambredessecrets.com/mk/i18n-index-sitemap.xml
you can take a look how it’s done on this links.
@gurumance
Now, for multilingual site You do not need to use different sitemaps. You can use only one multilingual sitemap. https://support.google.com/webmasters/answer/2620865?hl=en
Same as I did it in WP Multilang.