Still beating this dead horse I see. I just can't see how it's worth throwing away several months of development of Tiedemann as a starter on the off chance that he can retire MLB batters out of the bullpen. He would have needed to be called up in August to test this out, and then he would have likely been limited to low leverage spots at first with limited opportunities to actually get into games based on how many close games the team plays. Then he would have eventually needed to work his way into more trusted leverage innings over time with sustained success in lower pressure spots. This could very well remove Tiedemann as a legitimate depth starter option for next season as he would receive far fewer innings and not have a chance to build his innings base for the future, and this could even stretch a further season into 2025 with a further limited available workload.
Bringing him up would have necessitated sending down a deserving reliever to AAA or even cutting bait completely and losing an asset from the team as well. All of this would also entail starting his service clock early as previously mentioned as well. This could lead to situations such as Tiedemann becoming a super 2 player and reaching salary arbitration sooner, costing the team a very large extra amount of money for a single season potential bullpen bump.