"I know" = How do you know, please?
@S-Express is very knowledgeable and has much experience - he has tried to help the OP and explain his rationale. Don't you recognise the hubris you display by saying 'I know' whilst relegating my considered opinion to error.
"relegate it to a fact" - please use English.
"the correct chain tension" - in what way is this about the tension in the chain? This is an issue of chain length when users are seeking to use an RD outside its performance envelope.
"I do not believe anyone can present a counter argument strong enough to defeat that fact alone" What fact is that? That the Park Tools video suggests guidance? Several of the contributors have presented clear, valid and persuasive counter arguments to the suggestion (which you almost alone are opining) that the setup would be "fine".
My mantra here would be 'do no harm' and a chain as short as the image would risk self-harming if inadvertently used large/large. An extra link (one inch) would negate that risk and the only downside might be a bit of rub which would be noisily obvious to the rider, with an easy immediate action to stop it.
I know it because you didn't present any factual claims to your opinion. You just stated an opinion as if it was fact, without backing up what you said. Such as " No - the cage should not come above 4:30 o'clock."
I never relegated your opinion to Error. I Relegated your opinion to just that. An Opinion.
I respectfully ask you pay more attention here. You would of realized I was suggesting what the OP ended up doing, he agreed not to add any more chain links. Who has helped the OP more from that aspect? Your clear bias towards another user on here is laughably open; perhaps this is what caused your defensive and hostile reaction to my friendly comment.
The RD performance in that field about what the OP was asking is entirely and solely related to Chain Length.
Yes, the video suggests guidance that is factual.
You say "Several of the contributors have presented clear, valid and persuasive counter arguments to the suggestion that the set up would be fine"
What example are there of these highly acclaimed arguments?
By example, I mean a deep in-depth argument that concludes that his current chain length is inappropriate, which, bare in mind, would also have to propose a counter argument to the method shown in this video to a respectable degree.
Not even
@S-Express put an in-depth counter argument that the chain length was wrong in safety terms, in fact his argument was with me discussing why it's worth over-sizing said chain length.
Now as to what you've said at the end, I respect your idealogy of safety but not your tone toward me,
my tone has been to keep things mechanically functional,
@S-Express tone is to keep things avaliable, and yours is safety.
My recommendations of mechanical functionality goes hand-in-hand with your safety aspect, If you can shift into Large/Large without doing what we see on the Park Tool Video (i,e having inverted bends) then there's very little chance you're going to do any harm to your Derailleur and thus, yourself.
Exceptions can and will be made for everyone, but you will be Hard Pressed to see any derailleur present an immediate and destructive attitude toward rider safety when selecting large/large if you stay within the confines of the example shown within the Park Tool Video.
