Unaudited Condensed Consolidated Statements of Changes in Equity (Deficit) - USD ($) $ in Thousands	Total	Class A Common Stock	Common Stock Class A Common Stock	Common Stock Class V-1 Common Stock	Common Stock Class V-3 Common Stock	Additional Paid-in Capital - Warrants	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Noncontrolling Interest
Beginning balance (in shares) at Sep. 24, 2022			57,718,836	79,237,388	416,933,025
Beginning balance at Sep. 24, 2022	$ 68,940		$ 6	$ 8	$ 42	$ 58,126	$ 1,237,865	$ (2,294)	$ (1,286,569)	$ 61,756
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(123,402)								(13,311)	(110,091)
Issuance of common stock under stock plans, net of shares withheld for employee taxes (in shares)			1,677,078
Issuance of common stock under stock plans, net of shares withheld for employee taxes	(11,717)						(1,163)			(10,554)
Issuance of common stock under employee stock purchase plan, net of shares withheld for employee taxes (in shares)			98,171
Issuance of common stock under employee stock purchase plan, net of shares withheld for employee taxes	987						119			868
Exchange of Class V-1 and V-3 common stock (in shares)			1,789,604	(1,789,604)
Exchange of Class V-1 and V-3 common stock	0						200			(200)
Cancellation of Class V-1 common stock (in shares)				(367,694)
Stock-based compensation	84,763						9,131			75,632
Other comprehensive loss	1,870							208		1,662
Ending balance (in shares) at Mar. 25, 2023			61,283,689	77,080,090	416,933,025
Ending balance at Mar. 25, 2023	21,441		$ 6	$ 8	$ 42	58,126	1,246,152	(2,086)	(1,299,880)	19,073
Beginning balance (in shares) at Dec. 24, 2022			58,584,690	78,389,034	416,933,025
Beginning balance at Dec. 24, 2022	50,302		$ 6	$ 8	$ 42	58,126	1,243,217	(2,314)	(1,293,762)	44,979
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(55,416)								(6,118)	(49,298)
Issuance of common stock under stock plans, net of shares withheld for employee taxes (in shares)			1,659,578
Issuance of common stock under stock plans, net of shares withheld for employee taxes	(11,717)						(1,163)			(10,554)
Issuance of common stock under employee stock purchase plan, net of shares withheld for employee taxes (in shares)			98,171
Issuance of common stock under employee stock purchase plan, net of shares withheld for employee taxes	987						119			868
Exchange of Class V-1 and V-3 common stock (in shares)			941,250	(941,250)
Exchange of Class V-1 and V-3 common stock	0						90			(90)
Cancellation of Class V-1 common stock (in shares)				(367,694)
Stock-based compensation	35,223						3,889			31,334
Other comprehensive loss	2,062							228		1,834
Ending balance (in shares) at Mar. 25, 2023			61,283,689	77,080,090	416,933,025
Ending balance at Mar. 25, 2023	21,441		$ 6	$ 8	$ 42	58,126	1,246,152	(2,086)	(1,299,880)	19,073
Beginning balance (in shares) at Sep. 30, 2023			82,112,881	66,931,097	407,528,941
Beginning balance at Sep. 30, 2023	(2,716)		$ 8	$ 7	$ 41	58,126	1,254,022	(1,687)	(1,310,435)	(2,798)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(53,919)								(8,508)	(45,411)
Issuance of common stock under stock plans, net of shares withheld for employee taxes (in shares)			4,915,909
Issuance of common stock under stock plans, net of shares withheld for employee taxes	(3,153)						(3,103)			(50)
Issuance of common stock under employee stock purchase plan, net of shares withheld for employee taxes (in shares)			102,633
Issuance of common stock under employee stock purchase plan, net of shares withheld for employee taxes	3,500						3,500
Exchange of Class V-1 and V-3 common stock (in shares)			7,563,865	(4,369,120)	(3,194,745)
Exchange of Class V-1 and V-3 common stock	$ 0		$ 3	$ (2)	$ (1)		(155)			155
Issuance of common stock in connection with equity offering (in shares)	27,388,953	11,518,542	6,500,000
Issuance of common stock in connection with equity offering	$ 257,986		$ 1				257,985
Exercise of warrants (in shares)				15,870,411
Exercise of warrants	158,705			$ 3		(58,126)	216,828
Stock-based compensation	57,527						9,240			48,287
Other comprehensive loss	(4,304)							(686)		(3,618)
Ending balance (in shares) at Mar. 30, 2024			101,195,288	78,432,388	404,334,196
Ending balance at Mar. 30, 2024	413,626		$ 12	$ 8	$ 40	0	1,738,317	(2,373)	(1,318,943)	(3,435)
Beginning balance (in shares) at Dec. 30, 2023			85,106,588	81,489,643	406,512,941
Beginning balance at Dec. 30, 2023	171,875		$ 10	$ 8	$ 41		1,474,681	(1,770)	(1,312,363)	11,268
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(40,952)								(6,580)	(34,372)
Issuance of common stock under stock plans, net of shares withheld for employee taxes (in shares)			4,250,067
Issuance of common stock under stock plans, net of shares withheld for employee taxes	(3,095)						(3,095)
Issuance of common stock under employee stock purchase plan, net of shares withheld for employee taxes (in shares)			102,633
Issuance of common stock under employee stock purchase plan, net of shares withheld for employee taxes	3,500						3,500
Exchange of Class V-1 and V-3 common stock (in shares)			5,236,000	(3,057,255)	(2,178,745)
Exchange of Class V-1 and V-3 common stock	$ 0		$ 1		$ (1)		381			(381)
Issuance of common stock in connection with equity offering (in shares)	10,852,700	10,852,700	6,500,000
Issuance of common stock in connection with equity offering	$ 257,986		$ 1				257,985
Stock-based compensation	28,065						4,865			23,200
Other comprehensive loss	(3,753)							(603)		(3,150)
Ending balance (in shares) at Mar. 30, 2024			101,195,288	78,432,388	404,334,196
Ending balance at Mar. 30, 2024	$ 413,626		$ 12	$ 8	$ 40	$ 0	$ 1,738,317	$ (2,373)	$ (1,318,943)	$ (3,435)