Davi, your dates are substantially wrong on at least one point. You wrote:
“Manta's R&D began in 2013 - you are right about this
(3) Manta models were built and showcased to the public in 2015 - right about this
Three years later, there is not a single update from Fisher” - totally wrong, because...
Fisher acquired the Manta technology and hired Alexandre in April 2017. It says so right on Alexandre’s LinkedIn page.
https://www.linkedin.com/in/tartar-alexandre-b7131b99/
So Fisher has been involved for 12 months.
As far as hearing nothing from Fisher, Carl Moreland at Fisher has posted on another forum on 21 Feb 18...
“Yes, there is a new PI in the works, that is no secret. It's not on my bench, rather it's designed by our guy in France, Alexandre. The electronics are done, we're just trying to get a decent (& waterproof) mechanical enclosure designed for it. At FTP, that's not a fast process, but neither is anything else we do. Spring is out; Summer is highly unlikely; Fall, maybe. No promises.”
Carl also posted on another forum on 22 June 17 exactly how they he and Alexandre came together.
“I saw a fellow on Geotech talking about a new PI design he developed. 99% of the time people who say they got something, don't really got something, and it takes very little time or effort to find out they got nothing. All I have to do is say "show me," and they either show me or they start bluffing. If the bluffing starts, I'm done. This guy didn't bluff, he packed up his prototype and sent it to me to evaluate. It worked so well we not only bought the design, we hired the guy full-time.”
If you are signed up for the Geotech forum, you can find the 10 May 2015 post where Alexandre discloses the underlying technology and states among other things..
“Currently I work in research in the field of UHF rfid for a very big private compagny but I developed metal detectors since the age of 14 and I am 35 years old.
I also worked in industry and french military electronic development.
I spend 40 hours every week in addition to my work on the metal detectors.
I worked alone on over 35 versions and models.
Currently we are working to 3 people, tinkerer, willy.bayot and me on new revolutionary technologies.
It is not for commercial purposes, for the moment this is for fun.”
And he further states...
“I intend to produce some units to the end of the year, as Eric Foster did in his time, I will build in the future few detectors, approximate price € 2500 to € 3000”
And...
“This represents 15,000 hours of development over the last 10 years .... It is a true passion”
If they introduce the Fisher PI - fully productionized, in a lightweight ergonomic package, for less than $2000 by this time next year, I think it will be pretty rapid progress.
If you want to see some discussion on how the latest prototypes are performing in Brittany, LE JAG is testing them - you can google his name - or try this phrase in google search “new fisher manta frank in nh” that should take you to a search result which will help