First of all let me congratulate you for teaching correctly that there were two Sabbaths in the week of Jesus death and resurrection. The Church as a whole misses this completely. Please allow me to share a couple of scriptures that shed additional light on this subject.
Mark 16:1 says that after the Sabbath was past they bought the spices that they might anoint Him. Luke 23:56 says that they returned and prepared the spices then rested on the Sabbath. Luke 24:1 They came to the tomb very early on the first day of the week bringing the spices that they had prepared.
A Thursday “Unleavened Bread” High Day Sabbath rest followed by a busy Friday of buying and preparing the spices then a Saturday weekly Sabbath rest is the only way that these two Scriptures can both be true. Your scenario of back to back Sabbaths on Fri and Sat after a Thus sundown burial leaves zero time for Mark16:1 and Luke 23:56 to take place.
It looks like you’re advocating a Wednesday crucifixion. I alluded to several objections I have to this in the article, and your scenario gives me a chance to explain one of them in greater detail; the problem with having a regular day between the two Sabbaths.
In Israel, denying burial to the dead was and is considered to be disrespectful to the body. Therefore Jewish law requires that every effort be made to complete the burial process within 24 hours of death. Only a Sabbath can extend this time. Had Friday not been a special Sabbath the women would have completed the burial then, as required by law. Only consecutive Sabbaths on Friday and Saturday would have allowed them to delay their work until Sunday.
As you indicate, Luke 23:56 says the women saw where the Lord’s body was put, then went home to prepare spices and perfumes, and then rested on the Sabbath. Mark 16:1 says when the Sabbath was over they bought spices to anoint the body. Mark 16:2 and Luke 24:1 say very early on the first day of the week, just after sunrise, they went to the tomb.
I believe Luke 23:56 refers to the special Sabbath John mentioned (John 19:31) which was the beginning of the Feast of Unleavened bread. Mark 16:1 refers to the Saturday Sabbath which ended at sundown Saturday evening. The women would have been able to purchase the additional spices as soon as the sun set on Saturday evening and have them ready to use when they set out for the tomb early Sunday morning.
Even today, the end of the Sabbath in Israel means shops and restaurants can re-open and typically do a brisk Saturday evening business. This would especially be true with back to back Sabbaths.