Yes I can definitely confirm that! However here is my recent KQ to KQ transfer experience at ADD (as posted on the premium fare deals section too):

2st stop of 4h: Due to a schedule change of the inbound flight (KQ452 instead of KQ404) overnight layover at ADD went from 8h to 4h, which was a good news actually.
Upon disembarking, considering the previous story, I went straight to immigration to ask the single entry visa, but I commented on the fact that is was pity that no one could get the transit visas directly here at the counter. The kind officer anwered me to go upstairs at ET transfer desk. From here a cool chap dealt with the situation. He took the luggage tags and next flight booking reference and said that luggages will be transfered to NBO and onward on KQ flights and I will need to collect the BP upon boarding at the gate. Really I could not believe him and kept thinking what will go wrong - but I did not have too many options either. After, I was admitted to the much better Cloud 9 lounge (while flying Eco with KQ and without BP...) whereas few days ago, entry was only permitted at the Gold lounge ( flying J and holding a BP ).

I proceeded to the gate relatively early, and good news the BPs were printed. Staff asked if I had luggages (yes 2) but I was not given tags by one of their colleagues who told me to not to worry as they will go to KGL via NBO.

At NBO, agent Victoria from the service desk near gate 15, after a long puzzled stare, worked wonders and confirmed me before boarding to KGL that both bags were retrieved and on the way to the final destination where I got upgraded for free from KQ.
All in all a stressful but positive 2nd experience which ended very well. however I can not certify this is the standard transit non ET/*A procedure at ADD, but for sure they can do it.