Is my idea feasible? and is there any recommended manufacturer or chip (for PCIe fanout)?
No suggestion on this. Hope someone may have experience can be shared.
The discussion in this post is worthy of your reference：
Jetson Nano PCIE configration - Jetson & Embedded Systems / Jetson Nano - NVIDIA Developer Forums
I have found some ICs which named “PCIe gen2 packet switch”:
ICs:
Diodes | 3port 8lane: PI7C9X2G308GP
Diodes | 6port 8lane: PI7C9X2G608EL
Diodes | 6port 8lane: PI7C9X2G608GP
Diodes | 8port 8lane: PI7C9X2G808PR
ASMedia | 7port 12lane: ASM1812I
ASMedia | 5port 6lane: ASM1806I
ASMedia | 7port 12lane: ASM1812
ASMedia | 5port 6lane: ASM1806
Broadcom | 8port 8lane: PEX 8608
Broadcom | 8port 8lane: PEX 8609
Broadcom | 6port 6lane: PEX 8606
Renesas | 5port 8lane: 89HPES8T5A
Diodes product list: Diodes 8-lane PCIe 2.0 packet switch list
ASMedia product list: PCIe Bridge Controller|ASMedia Technology Inc.
Broadcom product list: PCI Express 开关 (broadcom.cn)
Renesas product list: PCI Express® Gen2/Gen3 Signal Integrity, Switching and Bridging Products Overview
Welcome everyone to append the PCIe packet switch ICs to this topic.