There is a famous teshuvah of the Radba”z on the topic of a person in prison who can choose one day a year to go out – should be wait for Yom Kippur, the most chashuv day of the year, should he maybe wait for Purim where he gets pirsumei nisa as well as mikra megilah, or should he choose the very next day on the calendar and not wait at all? Radba”z says “ain ma’avirin al hamitzvos” – take the very next day.
The Chacham Tzvi argues that this is against a mefurash gemara. There is a sugya (Menachos 49a) that debates what to do if you have only one animal left in storage to use for korbanos and it’s Shabbos afternoon – should you use it to be makriv the korban musaf of Shabbos, as Shabbos is mekudash, or should you hold it until tomorrow and be makriv Sunday morning’s tamid because of the importance of tamid. Based on the logic of the Radbaz, just like you don’t wait for Yom Kippur or for Purim because “ain ma’avirin al hamitzvos,” it should be pashut that you should offer the musaf that is obligatory today instead of waiting for the tamid of tomorrow. What’s the gemara’s safeik? QED that since there is a safeik, the Radbaz is wrong.
How could you be mechaleik between the cases? I'll let you think before writing anything.