I don't think so. Or does WD say the My Net 750 has got WPA3-compliant hardware? Without the proper hardware, you won't get WPA3-support even if the driver offers it.
Edit:
According to https://openwrt.org/toh/hwdata/westerndigital/westerndigital_mynetn750, the device has been manufactured long (5 years) before WPA3 has been invented.
So, in my opinion the chances of WPA3-support are non-existent.
ar9344/ ar9380 (both ath9k) has no problems with WPA3/ SAE, it just works with modern OpenWrt (including hardware accelerated IEEE 802.11w) - your zoo of non-linux clients however might be more difficult.
In v21.x i had WPA3 support, by that version was not stable in other ways... 
I didn't knew that, on the other hand there aren't many informations available on the net. Thank you for the clarification.
Why i should download the OpenWRT v19.07.10 from https://firmware-selector.openwrt.org/?version=19.07.10&target=ath79%2Fgeneric&id=wd_mynet-n750 instead from [OpenWrt Wiki] Western Digital My Net N750 ??
Thank you very very much for your feedback(s)...
My question was about a > 19.x version, prefered 22.x, with a special fix/patch for the Western Digital N750?
@hnyman @jow @tmomas, did version 19 have WPA3?
Or a way to install (and perhaps use the custom firmware selector to do so)?
@ all (Has a cause of the anamoly issue been discovered?)
I had no issues with v 19, it did not matter where I downloaded.
"did version 19 have WPA3"
-> No!
"I had no issues with v 19"
-> Same for me, my 2nd WD N750 still run with that version without any problems...
QUESTION IS STILL PENDENT: Is there a customized (custom compiled) v21.x or v22.x version for the WD N750 which has a fix / bypass / workaround for that issues...?
This is the best info I have:
I'm sorry I can't help with further details. I have been running version 22 on 4 devices. I have been posting updates in the threads about any issues. 1 2 have experienced 0 issues since flashing (it has the least config/file changes). Longest Uptime: 20+ days thus far (was on Solar/battery and I disconnected yesterday to maintenance the battery).
The 2nd I used a custom firmware (with the packages I need pre installed) I had no issues until one day LuCI and CLI stopped responding except to busybox. I rebooted and installed a firmware without LuCI. Uptime: 17 days so far.
Here's the post on all 4 again: Upgrade from Barrier Breaker 14.07 to latest 21.02 (WD My Net N750) - #36 by lleachii
I provided the link to the Firmware Selector - the downloads site was also provided.
(FYI I have a 5th device that's still running 18 or 19 - I left it untouched for future testing - in case this issue caused flash corruption.)
EDIT:
4 devices:
Devices 1 and 2 have:
base-files busybox ca-bundle dnsmasq dropbear firewall4 fstools kmod-ath9k kmod-gpio-button-hotplug kmod-nft-offload kmod-usb2 libc libgcc libustream-wolfssl logd mtd netifd nftables odhcp6c odhcpd-ipv6only opkg ppp ppp-mod-pppoe procd procd-seccomp procd-ujail swconfig uboot-envtools uci uclient-fetch urandom-seed urngd wpad-basic-wolfssl
This is the default list on the Firmware Selector for 22.02.3. These work for me without issues.
I've added the following without issues:
wireguard-tools snmpd tcpdump
As I noted 2 devices have 0 issues:
Also:
I remotely sysugraded Device B from 22.03.0 to 22.03.1. It did not have LuCI installed in the image. The device did not seem to reboot successfully. I'm waiting on remote hands at the location to troubleshoot. I'll update soon.
I was told in another thread to announce if such things occur. Not sure why the OP assumed I upgraded the other machine; but nonetheless - in this case I in fact did upgrade the N750 and I am noting the issue.
On this failed flash, I added to the Firmware Selector:
wireguard-tools kmod-wireguard snmpd tcpdump
This produced an image without LuCI
I upgraded another device today (Device C) - after looking at the file sizes of all packages. tcpdump adds nearly 1 MB additional including its dependencies. So I only added:
wireguard-tools kmod-wireguard snmpd
This again made an image without LuCI - that upgraded successfully.
So it's definitely the image size causing issues. I'm guessing when luci-ssl became the default web GUI is when most people not adding packages started noticing.
Thank you very much for your feedbacks.
Maybe now there are any stable (maybe custom) images available for the Western Digital N750?
Otherwise: Are there any other opensouce linux router os for that device? (ddwrt, Tomato?)
Yes, use small image.
https://firmware-selector.openwrt.org/?version=22.03.3&target=ath79%2Fgeneric&id=wd_mynet-n750
(Noted quite a few times above. I have mutiple devices running 22.03.3 with 0 issues.)
Seems like a question for those forums.
Thank you very much for your feedback. Is that image with out without Web GUI?
ok thx 
Additional question: How is that possible that something that runs on application layer (Luci) will make a difference on such "low-level"-Filesystem errors?
Very special i.m.o.!
Maybe somebody is able to explain me that...?
THank you very very much for your feedback(s)
Already explained, see above.
Is there an actual issue you're experiencing?
Also: Upgrade from Barrier Breaker 14.07 to latest 21.02 (WD My Net N750) - #54 by lleachii
(Not sure why you're repeating your inquires.)
Thank you very much for your feedback.
"Is there an actual issue you're experiencing?"
No, currently not...