Indeed, הֵיכַ֥ל has a range of meanings. 1 Samuel 1:9 refers to meaning 2a below as God's house, not a pompus palace:
Brown-Driver-Briggs
1 rather seld. (royal) palace (so almost always in Assyrian); of Ahab 1 Kings 21:1,
of king of Babylon 2 Kings 20:18 = Isaiah 38:17; 2Chronicles 36:7
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2 of palace of God considered as king, = house of God or of ׳י, temple (compare ׳הַה Isaiah 6:1 e. below where prophet sees אדני ישֵׁב עַלכִּֿסֵּא):
a. of early, pre-Solomonic house at Shiloh ׳הֵיכַל י 1 Samuel 1:9; 1 Samuel 3:3 (= ׳בֵּית י 1 Samuel 1:7; 1 Samuel 3:15; מֶּתַח אֹהֶל מוֺעֵד 1 Samuel 2:22 omitted by ᵐ5 We Klo Dr) with doors (דלתות, 1 Samuel 3:15) & a doorpost (מזוזה 1 Samuel 1:9) (compare 2 Samuel 22:7 = Psalm 18:7 e below).
b. of Solomon's temple: specifically the hall or nave of the temple (the holy place, distinguished from the דְּבִּיר the inner sanctuary, the Holy of Holies, and with this included in the more General term
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c. hall or nave of Ezekiel's temple, the holy place
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d. general designation of 2 nd temple
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e. of the heavenly temple where ׳י sits enthroned Isaiah 6:1; his abode in the heavens
The word has two general meanings: a secular king's palace and God's temple.
The second meaning is further divided into 5 nuances. Note how the nuance changed or evolved over time.
Ellicott describes it as a permanent structure and not a mobile tent.
The seat upon which Eli is represented as usually sitting (see 1Samuel 4:18) was evidently a chair or throne of state, where the high-priestly judge sat at certain times to administer justice and to transact business. The Hebrew word rendered here "post," and the expression "doors of the house" (1Samuel 3:15), seem to suggest that now a permanent home had been erected for the sanctuary: something of a building, possibly of stone, surrounding the Tabernacle had been built.
