rtl838x is rather well supported at this time (at least for the devices that already have binary images available in the realtek target), it's working pretty nicely. However you should be comfortable to attach a serial console (3.3V!) and don't feel scared about loading and booting an initramfs image over tftp, before flashing the sysupgrade image from there. If any of the above scares you, it's probably not a good idea for now.
The bigger issue complex is not
realtek specific per se, but a consequence of the current state of DSA support in OpenWrt right now (not just affecting
realtek, but also
mvebu and the various
ramips targets - as well as
ipq806x within short time). While netifd has learned about the basics (and a bit more) by now, luci integration is still missing (and while there is a pull request adding a prototype, it's not merged yet). If you want to exploit the features and capabilities of L2 managed switches to their full extent and set up multiple VLANs, you will have to be able to collect information based on the sparse documentation and sources for the time being - furthermore it would be advantageous to be familiar with
Given that both DSA support in OpenWrt and the realtek target are still rather new, you should be rather flexible, willing to learn and able to work on it on your own, without requiring lots of documentation or pretty webinterfaces for now. There are bound to be changes (e.g. the current default setup setting up the management interface on port 1 only via
VID100), but the hardware support itself is rather nice and stable already.
If you are familiar with OpenWrt and not afraid of using the cli or to edit configuration files, this could be a rather rewarding learning experience.