Bit late to the party but as luck would have it I'm researching one of these at the moment.
That monorail coaster with the upside down triangle track operated for ages (I am unclear if its the same one as Eclaire or a different installation). It was still running in 2007 in the south of France. And was built by Mack of all people.
It ran at Pirat' Park and the nearby Luna Park for a while under the name R2000.
Here are some shots from a trip report there in 2007
Trip Report (in French) https://forum.coastersworld.fr/les-trip-reports/(tr)-r2000-et-europark-vias-plage-2007/
A second model existed in the USA and was a racing version. It ran at Playland in Jacksonville Beach in Florida in the 70s and I believe was at the Texas State Fair at least once.
Here is a shot of it in Jacksonville Beach
Photo credit Kenny Rutherford
The Jacksonville Beach one is an Elusive little Bu**er. That is the only shot I have seen so far.
So following up the bizzare mack R2000 racing coaster from Jacksonville Beach seen in my post above.
I have tracked it down finally thanks to some help from a friend in South America.
The ride was moved to Play Center in Sao Paulo, Brazil where it ran for a few years before being sold to a travelling fair and was eventually placed in storage.
The good news is the ride is still in storage and viable and has been sold this year to a travelling park called Mega Park where it is expected to run again soon.
Not a coaster but still an interesting concept from Japanese ride designers Hoei Sangyo. (who are always great for a wacky concept)
This is the Crystal Bird drop tower which profiles each side of the drop tower with a different humped track design.
How comfortable this would actually be remains to be seen but I still kind of want to find out.