Gentoo runs way smoother and is actually open source and compatible with most hardware. All you need is hardened Gentoo w/ Secure Boot, a custom open source RISC-V desktop SBC w/ verilog and mainline Linux support / UberDDR3 / MIAOW GPUs / OpenPHY / iCE40 FPGA, an open ath9k 802.11 Wifi PCIe, a Modos paper display and a flash drive w/ decryption key to turn it on. Use VexRiscV chips. Will still need a development board (like a SiFive HiFivePremierP550) for writing and programming the board, and soldering equipment + microscopes.

Also, "fully Libre'd Thinkpads" don't exist. Even if you wiped the firmware to the SoC, you still have the display, which is proprietary, the hard drive which is proprietary (to which there's only one company on Earth that manufactures open source hard drives, and that's Raptor Computing Systems which uses them for their Talos PCs that costs $15,000, and even if you were using an open HD, you'd still need Faraday protection to prevent sidechanneling) and so on.

You will also need:

>Banana Pi BPI-RV2 and Wio Lite RISC-V board integrates a RISC-V microcontroller (VexRiscV, again) for modem/router functionality
>FPGA/Soft-MAC Wi-Fi modules for fully open 802.11 networking experiments; setup includes an FPGA development board (e.g., Lattice iCE40 or TinyFPGA), and software stack such as Open80211, connected via USB or GPIO to SBC and optionally bridged to RISC-V boards
>SiFive FE310 as an open-hardware USB-to-UART/SPI/I2C bridge replacement, plus a Bus Pirate (open-hardware) when you want a flexible serial/GPIO bridge
>Connect your ethernet cables to your proprietary default ISP hardware and you can now use IP over DHCP to establish a private network connection

Why all the hype over Arch? Gentoo runs way smoother and is actually open source and compatible with most hardware. All you need is hardened Gentoo w/ Secure Boot, a custom open source RISC-V desktop SBC w/ verilog and mainline Linux support / UberDDR3 / MIAOW GPUs / proven open PHY stack / iCE40 FPGA, an open ath9k 802.11 Wifi PCIe, a Modos paper display and a flash drive w/ decryption key to turn it on. Use VexRiscV chips. Will still need a SiFive development board (like a SiFive HiFivePremierP550) for writing and programming the board, and soldering equipment + microscopes.

Also, "fully Libre'd Thinkpads" don't exist. Even if you wiped the firmware to the SoC, you still have the display, which is proprietary, the hard drive which is proprietary (to which there's only one company on Earth that manufactures open source hard drives, and that's Raptor Computing Systems which uses them for their Talos PCs that costs $15,000, and even if you were using an open HD, you'd still need Faraday protection to prevent sidechanneling) and so on.