The Collateral Tabernacle

Rashi: These are the numbers
all the weights of the donations for the Mishkan were counted in this parasha - [that] of silver, of gold, and of copper and also all its implements for all its work were counted.

the Mishkan, the Mishkan:
...the Temple...was taken as security...for Israel’s iniquities... The word is written twice. This alludes to the Temple, which was taken as security [in Hebrew, 'mashkon'] for Israel’s iniquities by the two destructions. [The Temple was taken away twice as a collateral for Israel’s sins.] When Israel fully repents, the Third Temple will be built.

the Mishkan of the Testimony:
[The Mishkan] was testimony for Israel that G‑d forgave them for the incident of the [Golden] Calf, for He caused His Shechinah to rest among them [there].

Baal HaTurim: The verse repeats the word mishkan/tabernacle, which can be read as Mashkon/collateral, for the 2 times the Temple was taken as collateral against the sins of Israel. …Moreover the gematria of Mishkan (410) hints to the number of years during which there was evidence that the Shechinah dwelled among the Jewish people, in the first Temple which stood for 410 years.

Ramban: The term Mishkan/Tabernacle itself means the curtains of fine-twined linen which were so called both when the command was given and at the construction of the Mishkan. The term Mishkan HaEdut/"the Tabernacle of the Testimony" includes the entire building, which is the Tabernacle, made to house the [two] tablets of Testimony

Ohr HaChayim: Shemot Rabba 51 explains the erection of the Mishkan was to atone for the Golden Calf. We are told in Chulin 5 that being guilty of idolatry is equal to violating all the commandments of the Torah. So perhaps "these are the reckonings of the Mishkan" should be translated the way Onkelos renders them, "these are the commandments of the Mishkan", namely the Mishkan equals all of G‑d's commandments and thereby compensated for the sin of the Golden Calf. There is a hint of this when we look at the gematria of the words "Pekudei HaMishkan", which equals 615, the 613 commandments plus 2 for the two tablets they were recorded on; thus the meaning of the first word, "these." These [615] will help G‑d forget the 613 commandments Israel violated when making the Golden Calf.

Zohar Pekudei 221:
...when the construction of the Tabernacle took place, the Other Side roamed about to bring accusations. "These are the accounts of the Tabernacle." Come and see: At the time when the construction of the Tabernacle took place, the Other Side roamed about to bring accusations. He found no flaw in the faithfulness of the craftsmen, so G‑d caused him to yield before Moses. And he had to check their worthiness in spite of himself and to acknowledge it before all. This is the mystery of the verse, "These are the accounts of the Tabernacle." And we explained that "These" is the same as in "even these may forget" (Isaiah 49:15). It is also written, "as they were counted according to the commandment of Moses." For there, all was counted and numbered, until the accounting of the Tabernacle was complete before Moses and all of Israel.