@Curious ... can't believe you got the old guy with a crap fh to talk about FHs again.
Buuuut ... I find the Curious fh holy grail quest entertaining ... and a nice change when the entertainment isn't an existential threat.
Based on my ttw years
... the FH a la carte choices covers a lot of territory ... traditional, wta, atp without flip, atp w/little flip, atp w/max flip, arm behind body, arm on hitting side of body, bent arms, straight arms, arms with wrist extension, all kinds of concerns what that extra arm/hand is doing, armless FHs and arming FHs, eastern grips and all the other wrong
FH grips, unit turns and nipples forward sans turn, hips or not to hip, isr esr irs, yada yada yada.
In short ... the FH rabbit hole is infinite ... but who doesn't like rabbits?
Perhaps a suggestion of two large buckets to narrow your quest:
1) hand position in context of body line
2) pat the dog vs rec tennis court is no place for a dog
Which gets me to the real reason for this post ... found this cool video of Agassi and wanted to post it for any reason ... your FH will do.
So ... Agassi isn't a bad starting point for the two big FH buckets I listed:
1) Agassi hits is FH with his hand pretty far out from his body line. Do you want to hit with hand closer to your body line? Behind ok?
2) Agassi isn't big into patting that dog ... what do we call this ... loop? I see a rec player getting close to Agassi's FH style, and enjoying a lifetime of HITTING a FH. With trying to Fed, flip, pat the dog ... I see a lifetime of poorly timed 30 mph FHs that are not satisfying.
For example ... when I see your nice yellow shirted friend hit his FH I have the following two thoughts ... in this order:
1) that ptd FH is a smooth as silk
2) now please whisper in his ear ... hit that sucker with your arm muscles for another 20 mph.
Hope this helps.
Oh ... forgot to summarize:
1) hit with hand "almost" behind you ... but still just in front of body line ... and enjoy years of a full backswing
2) Agassi loop is your friend ... dogs are not man's best friend on a rec tennis court.
OK ... I will be exiting from the back door ... good luck.