fans & ipmi on ampere emag with lenovo bmc

With recent exorbitant price hikes for electricity in Austria, I'm
looking how to reduce the fans on my eMAG HR330A when its idle.

There's no obvious sysctls related to fans, but there are IPMI
raw sequences available[1] which I can send to the remote BMC:

ipmitool -I lanplus -U ... -P ... -H ... raw 0x3c 0x14 etc

Has anybody got a better solution to managing fans & temperature?

# demsg
[14935] ipmi0: <IPMI System Interface> on acpi0
[14935] ipmi0: SSIF interface not supported on ACPI

# sysctl hw.ipmi dev.ipmi
hw.ipmi.cycle_wait: 10
hw.ipmi.wd_pretimeout_countdown: 120
hw.ipmi.wd_startup_countdown: 0
hw.ipmi.wd_shutdown_countdown: 0
hw.ipmi.wd_timer_actions: 3
hw.ipmi.wd_init_enable: 1
hw.ipmi.on: 1
dev.ipmi.0.%parent: acpi0
dev.ipmi.0.%pnpinfo: _HID=APMC0D8A _UID=0 _CID=IPI0001
dev.ipmi.0.%location: handle=\_SB_.I2C4.IPI_
dev.ipmi.0.%driver: ipmi
dev.ipmi.0.%desc: IPMI System Interface
dev.ipmi.%parent:

there is no /dev/ipmi device btw.

main-n258204-33de921ca874

[1]: https://download.lenovo.com/servers_pdf/bmc_command_list_specification_v0.1.1.pdf

A+
Dave