Yes, you would want to delete /etc/udev/rules.d/70-input-repeat.rules because the final released fix will have this file in /lib/udev/rules.d/
By dev version do you mean you are on the osmc stretch-devel repo ? If so try updating again, I’ve pushed a further version of the eventlircd package (1.3.8) not long after you posted with further tweaks which I hope are final now.
As above if you have previously created the file in /etc/udev/rules.d/ you will need to delete it or it will override the one in the updated package.
You might want to update again as well as I’ve tweaked it a bit further since your post. Don’t worry about the ir-keytable errors in the log - they occur because it tries to adjust the delay and period setting of all libinput devices, and not all of them will accept such settings. (So they harmlessly ignore it, but an error is logged)