The latest 3.18 pre-release (beta) version of Rufus, the popular bootable USB media creation software, adds the ability to bypass Windows 11 system requirements for in-place upgrades too.
Earlier, with version 3.16 Beta 2, Rufus had already received the option for bypassing the stringent system requirements for Windows 11 with the "Extended" installation feature. Though, the option was only available for clean installations. However, now with Rufus 3.18, the feature can be availed for in-place upgrades too.
The official changlog says:
Add bypass of Windows 11 restrictions for in-place upgrades
It seems like these strict system requirements for Windows 11, like the presence of TPM 2.0, Secure Boot, among others, might have played a big part in the slow down of Windows 11 adoption as per the latest AdDuplex data. And this is despite Microsoft's effort to accelerate the rollout of Windows 11.
Rufus 3.18 beta also fixes another Windows 11 related bug that broke the "ISO → ESP creation" feature. The bug (#1855) would prevent the creation of EFI system partition (ESP) on Windows 11 devices and throw an error code "0xC00305B4".
The changelog for this bug says:
Fix ISO → ESP creation when running on Windows 11 (#1855)
You can view the full release notes for and download Rufus 3.18 beta here.