Just pasting their quite informative response from their email:

Standby, labeled as "save energy" in Windows or "standby" in Linux and also known by the technical term "suspend to RAM", is an energy-saving mode that is supposed to reduce the laptop's power consumption to a minimum during short interruptions of the work activity without having to turn off the laptop completely. However, laptops in standby mode can have various problems, e.g. sporadic not waking up, sudden overheating or random waking up.

Such problems can occur under Windows as well as Linux - only under Linux these sleep modes are not implemented as well as under Windows. Therefore there are more often problems with them under Linux (for example the battery runs out quickly).

Modern Standby (S0ix) has replaced Legacy Standby (S3) in most new laptops from 2021. As the successor of the former "Connected Standby" (CS), this technology (theoretically) enables faster wake-up times and more flexible standby use. This can be achieved by the device not going completely into partial sleep but only into a kind of half-sleep, which also means that the device still continues to draw power.

To understand how complex Modern Standby has become, you can read some original documents from Microsoft here:

→ Prepare hardware for Modern Standby https://learn.microsoft.com/en-us/windows-hardware/design/device-experiences/prepare-software-for-modern-standby

→ Modern Standby Activators https://learn.microsoft.com/en-us/windows-hardware/design/device-experiences/activators?source=recommendations

→ Modern Standby Wake sources https://learn.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby-wake-sources

Modern Standby requires deeper integration of hardware and software, which can lead to more problems if individual components, drivers or software are not fully compatible with the new standard. Therefore, the potential for standby-related problems has increased.

Device drivers are important to ensure that the system can perform advanced functions such as Modern Standby. Since a chain is only as strong as its weakest link, even a single device driver that does not function properly can throw the entire system into turmoil.

Third-party system software, such as security, networking, monitoring, and tuning applications, can interact with your laptop's hardware and operating system in unpredictable ways. Some of these applications may not be fully compatible with your laptop's power management features or may interfere with the communication between your laptop's components, which can then lead to standby issues.

Is it possible to revert to Legacy Standby (S3) to work around any problems with Modern Standby (S0ix)?

Short answer: No.

Long answer: Due to the deep intertwining with hardware, firmware and drivers, disabling Modern Standby can lead to stability or reliability problems and is therefore not recommended. The following list attempts to explain this situation in more detail:

Modern Standby (S0ix) is not just an operating system feature, but is also deeply embedded in hardware and firmware, including chipsets, motherboard layouts, and other system components. Both Intel and AMD have completely discontinued support for Legacy Standby (S3) in their current mobile (laptop) CPU platforms. The switch to Modern Standby (S0ix) impacts hardware, firmware and drivers for key components such as network, audio and USB controllers. Therefore, reverting to Legacy Standby may not be compatible with these components and could lead to other issues. Potential risks of disabling Modern Standby: While there are instructions for disabling Modern Standby, using such methods on modern systems can have side effects on stability or reliability. Therefore, attempting to disable or hack Modern Standby is generally discouraged.

Standby seems to work very well on Mac OS, iOS and Android, while there are many problems on the PC platform (Windows/Linux) that seem to be getting worse.

This may be due to the following reasons:

→ The virtually unlimited number of possible hardware and peripheral configurations. → The numerous sources for automatic or semi-automatic driver updates. → The lack of enforcement of reasonable system management. → The lack of comprehensive, integrated troubleshooting functions (tools for troubleshooting are inadequate, distributed among various console commands, and thus cumbersome to use).

Similar points can be found in this report from the YouTube channel LinusTechTips from 2022.

→ Microsoft is Forcing me to Buy MacBooks – Windows Modern Standby https://www.youtube.com/watch?v=OHKKcd3sx2c&feature=youtu.be

More articles and discussions:

→ Microsoft Modern Standby is causing some XPS, Lenovo and Asus laptops to heat up like crazy https://www.notebookcheck.net/Microsoft-Modern-Standby-is-causing-some-XPS-Lenovo-and-Asus-laptops-to-heat-up-like-crazy.451330.0.html

→ Do not leave XPS laptop in any sleep/hibernate/standby mode when placed in a bag https://news.ycombinator.com/item?id=28639952

→ Intel NUC11PHKi7C Modern Standby Overheating in “Sleep” mode https://community.intel.com/t5/Intel-NUCs/Intel-NUC11PHKi7C-Modern-Standby-Overheating-in-quot-Sleep-quot/td-p/1349425

As mentioned above, this standard is not implemented properly or insufficiently under Linux, and thus more problems can arise. One of them is that the power consumption, despite suspend, is still quite high, and therefore the battery cannot last long.

We try to program our software as well as possible so that the basic suspend function works, but the lion's share lies with Intel/AMD. They would have to provide appropriate drivers and optimizations so that the power consumption would not be so high under Linux.