I would like to very much thank everyone for the interesting responses. I apologize for not giving more details. We ride a tandem and tour with camping gear often, so 470lbs/214kg for riders+gear+bike. Weinmann zac19 rims/36hole/559. A rear rohloff hub, so no dish. I built something to calibrate my park gauge, after which I found that both wheels were higher than expected, at average of 120 kgf (variance of +/-20%). I like higher tension, but concerned that the rim (no eyelets, no nipple washers) will not support the nipples. Furthermore, the high spoke angle at the rim causes the nipple to angle significantly (good for spoke), but the asymmetry of nipple in hole (I suspect) will make it easier for the nipple to pull through rim.
So, back all off 1/4 turn to about 100kgf, or is that too low for a loaded tandem?
Thanks again.