Coming back to the question from earlier in the week: according to the Mordechai's opinion that you can wear a 4 cornered garment on shabbos without tzitzis because the issur of tying gives you a ptur ones from the mitzvah of tzitzis, why can't you use a kli that you have not toiveled on shabbos since you are ones and cannot bbe toivel the kli?
Rav Gestetner surprisingly does not point out that a similar question was already asked by R Shlomo Eiger (YD 28:20). The SA paskens that you can't shecht unless you have dirt prepared for kisuy ha'dam. Why not shecht and then if it turns out that you have no dirt, eg it is Yom Tov and you did not prepare any dirt in advance to not be muktzah, so what -- you are in a situation of ones and are therefore exempt from the mitzvah. What's the difference between putting on a talis knowing it has no tzitzis and you cannot tie any on and shechting knowing you have no dirt?
The Steipler (printed in Baba Basra in the new editions) says there is a big difference, and this will answer R Gestetner's question was well. Even if you put tzitzis on that talis tomorrow, it can't help you with the mitzvah of tzitzis that you have today. Tomorrow is a new opportunity to do tomorrow's mitzvah, but in terms of today, you lost the mitzvah. The same is not true of kisuy ha'dam or tevilas kelim. The mitzvah in those cases is to be toivel the kli, to cover the dam -- the mitzvah is on the cheftza, which will be the same tomorrow as it is today. If you delay the shechita or delay using the kli you haven't lost a mitzvah opportunity, you've simply postponed the same opportunity for a different time.
(Consider this a starting point on the issue.)