Just an update to my previous post here.
I have now moved LIBREELEC_DISK data storage form my SD card partition to my internal eMMC memory on my TX9 Pro S912 box following Kszaq's excellent instructions. The process was very easy and took only a few minutes and was a very logical easy to understadn process too. Also following the same instructions I moved my storage data across from the SD card to the new /dev/data LIBRELEC_DISK labeled internal memory so I woujld retain all my settings and suite of addons etc. The box booted up as before with nothing lost from my settings and add-ons etc. Truly excellent and yes I DO notice a difference in speed. It is not earth shattering speed differnce but I can say that so far the box is much snappier especially memory intensive procedures. Of course it is still slow with searchign for Server lists from many of the nameless addons and this was expected as that is an internet routing problem which we know is IMHO wrongly impaired by ISPs gettign involvred when theyu should not, and not helped by the removal of teh old US net neutrality sensible rules !!!
I also tried the reversal procedure and that worked fine too changing the labels back to how they were and of course my data was left untouched on my SD card data partition. Careful with the reversal instructions quoted though as you DO have to also issue the command to rename the SD card partition back to LIBREELEC_DISK again else I believe it will recreate a new data partition on the SD card and y ou would have lost all your original data. You can of course also recopy the up to date data from your internal memory storage to the SD card first too if you want.
Okay first a probably unrelated problem that has cropped up coincidentally I think and that is I get a reported error on the service "Universal - An Addons Toolkit" which I am not getitng on my other S905x boxes on which I have not moved the data storage to internal memory. As I say probably a coincidence. Has anyone else got this problem though. I do not know what the service addon even is, but assume it is an officlal KODI service ?????
Now I have an important question. I use other bootable SD cards for testing and running both newer and/or older firmware builds on my TX9 Pro box. So now that I have moved the storage to internal memory, what will happen when I change the bootable SD card for a different one which of course will still have the on-card original storage partition labelled LIBREELEC_DISK . Whcih one will Libreelec use when seeing two separate partitions both withthe same LIBREELEC-DISK label ?? If it uses both (doubtful) won't that cause some data corruptions. If it uses just the internal storage memory then it will be the wrong required storage build of settings and add-ons needed for the different bootable SD card's firmware version. Have not tried it yet as I do not want to corrupt my new internal storage partition for my LE 8.2.5 422 Chroma 10 bit build but would appreicate an answer if anyone knows.