Hi Jukka,
You already have this in current version. In fact, this feature was added in 5.98c in october 2018! Please read the news
https://www.swisslogforwindows.com/engli...5.htm#598c
In the My QTH you have a new field called "Operator call" which is also exported into ADIF. You simply have to add a MyQTH for each operator. Main call for every MyQTH will always be OH3AD and the Operator call the corresponding according the operator. You can set an easy MyQTH abbreviaton name to identify quickly which MyQTh should be selected according the Operator: OH3AD - OH3OJ, OH3AD - EA3GCV, etc. For LoTW and eQSL synch configuration, simply select the same Station Location and eQSL Nickname defined in TQSL in all your MyQTH for main call OH3AD. This way you will always know who are the operator for every QSO.
Best 73
