It depends on a lot of unstated details, so it’s not really possible to say simply yes or no.
For a pool server, accuracy in the single-digit milliseconds is more than enough to stay in the pool. For a pool monitor, on the other hand, I’d want appreciably less than 1 msec offsets seen locally, and as symmetric path as possible to handoff(s) to other ISPs (AS numbers).
There’s a previous thread here that discusses the age-old “bare metal only for NTP” which has become less mandatory depending on details like type of hypervisor, CPU virtualization support, etc: Cringe at thought of NTP server on a VM?
Would you say it’s fair to describe the price difference between business and residential internet pricing in China as “business internet subsidizes home (residential) internet”?
I presume when you say nearly all home internet is behind NAT, you’re talking about an ISP’s NAT, so that numerous homes share a single public IPv4 address? For clarity, it’s best to refer to that type of NAT as “CGNAT” (carrier-grade NAT). CGNAT implies no ability to forward NTP’s UDP port 123 to a specific device on the home network, so no possibility to host a public NTP server or any other service requiring a specific port or ports.
Regarding most NTP pool monitors being outside China, I’m pretty confident monitors inside China would be welcome. If you know people with systems in Chinese data centers interested in helping out, the IP traffic, CPU load and disk space involved are all very small. [1] You might get them to bring up a pool server first and introduce themselves on this forum. Note I do not represent the pool, I’m just an enthusiastic participant.
I think I recall but can’t find right now reading here a message where @Ask mentioned the possibility of donating a bare metal or VM system with good timekeeping (such as a GNSS-connected NTP server or appliance in the same datacenter) running Linux/FreeBSD which he would configure as a monitor. I don’t know if he really wants one more server to manage, though. If it were me I’d much prefer someone willing to manage it themselves. The basic requirements are Linux or FreeBSD with 24x7 solid symmetric connectivity and established ability to run Chrony or ntpd showing stable performance. Given advances in x86/x64 hardware virtualization assistance and type 1 hypervisors that use them, while bare metal is always preferable it is possible do manage well with a VM.
Thanks for the answer. I forgot that milliseconds are enough for the pool users My own servers were initially a hardware server (although on very old hardware) to which I add GPS receivers and get pps