My opinions and comments in no particular order.
Everyone knows that a crash puts a heck of a lot of stress on seats and restraints.
There are many factors which affect the stress on the track and fittings. Leverage, clamping strength, and friction are just some examples.
It is important that enough fasteners are installed to hold the seat fixtures to the track and to secure the track to the floor.
I don't believe that the OEM load rail L-tracks as factory designed/installed are up to the task of seat mounting without adding more track to frame/floor fasteners.
Aviation/aircraft parts and materials are held to different specifications as to manufacturing tolerance, design, weight, and strength as compared to vehicle components.
L-track type load rail is used in vehicles for load securement and seating. I recall that there are threads here which list the L-track for seats as used in the UK (Unwin as one example) so it can be done safely and meet standards. (I doubt that a DIY design/install would ever technically meet official standards though.)
This forum can offer opinions, methods, and criticism, but the final product is the total responsibility of the installer. There will never be concensus acheived here on the subject.
No matter how much design and documentation you have you will never be able to install a seat DIY that will technically, legally meet DOT specifications, or prevail in court should it fail. Don't even try to kid yourself.
An owner needs to decide whether the installation meets his/her standards while realizing that the seat installation may cause your vehicle to not pass a stringent regulatory safety inspection.
There are many, many previous discussions here on the forum about aftermarket and DIY seat installations.
vic