1) I've talked about Machado extensions (amongst the group) going back 8 years here. Search would only take me back to 2017 (maybe I did something wrong, but there's a Machado Extension thread from 2014 (I think) where I talk about this exact thing. I've referenced many more times over the years. Very few people, if any, have endorsed the notion that your approach to a player can or should have any impact no the long-term considerations.
The Orioles treated Manny better (well better) than the Padres treated Tatis in terms of service+. We don't have to re-hash that conversation, there's plenty of text on it, still stand by my positions which is in line with what just happened in the SD/Tatis contract. I put the same type of thing in the Rutschman thread recently. You can give it away if you like, I think players should respect how they are treated because there's a tangible cost value to decisions (discuss it all of the time).
2) We should confuse the 'service time manipulation' of Boras clients with other players/agents. You aren't getting anything back from a Boras client unless you do something ridiculous. Ignore the banter of a Boras client.
3) People are getting the Longoria situation generally wrong. Talked about it here and back on the Sun Boards.
4) If you are competitive, there's less excitement about 'prospect promotion' because you are competing. You Win Now, Win Later plan accounts for all of that stuff, if you're smart.
5) I don't think Diaz is anything (league average would be a good result for him) but what's true about his situation and every situation is that Player Opportunity is zero balance. For one guy to play, it comes at the expense of someone else. Everyone can't play. We aren't going to learn anything about a guy over a partial season or a whole season or even 2 seasons that is typically going to change an approach. Again, it's 1SP.
6) There's a reason to manipulate time beyond Service. People ignore or mock that, I think the Orioles are doing it (intentionally). You really don't need to manage service of guys you aren't keeping for 6 years.