Update:
Install went well, healed nicely.
I can read it quite well with my ACR122.
My Note 9 can also read it but it is hard to get the positioning right in such a large area like my arm but I can do it quite reliably.
Minimal luck with the KBR1, It takes about 45 seconds for me to find a sweet spot where as with my NExT and xSIID it reads them easily.
Overall I am happy with the choice to install there but it would be irritating for a tag I use more frequently unless I could use my ACR122 *wink* *wink*