i had the privilege of going aboard DIANNE'S ROSE the small houseboat mentioned in the video(Cheap Composting Toilet) OP827 shared above
https://www.roydesignedthat.com/composting-toilet.html
the occasion was at the PlyWooden Boat Festival in Port Aransas, Tx after Roy n his loverly bride Dianne had camped in the boat all the way from their home north of Toronto, Ontario Canada which was about 2000± miles one way
their composting toilet was located in the WC behind a curtain and whilst aboard i snooped all over and found no odor even in the south Texas heat
Roy and Dianne do use their composted byproduct to enrich their garden unlike most reading this are likely to do
IIRC Roy did use a separate pee bottle which reduced the liquid volume
my personal research got serious after visiting the Schreyer's Dianne's Rose and found a consensus on separating the pee as much as possible to reduce the odor
separators can be bought online or DIY
systems can simply be boxed
a GIGGLE search for "urine separating composting toilet" will offer up a plethora of designs w/ lotsa pics on how to DYI
the options for managing human waste are many
search with an open mind
BON CHANCE
sw