I guess it is the obvious answer, but it depends which you prefer the sound of.
If you run UA5 (digital) into the R44, the R44 would just be a bit bucket at that point and it wouldn't matter that you had yours Oade modded, since the Oade mod only changes the analog input stage, not the digital input stage. I wouldn't run the UA5 analog into the R44 since the UA5 doesn't have a true preamp only output, the analog outputs of the UA5 go through the internal A/D conversion process, so it actually would be analog in > internal A/D > internal D/A > analog out (and then analog in to the R44 > internal A/D conversion again).