Hello BVH,
I've just had a look to check, and the Hinsz Bovenkerk sample set's 'Bovenkerk-Tremulant' folder contains waveforms for Hauptwerk's native tremulant model. They aren't separate ranks of pipe samples. Only the Vox Humana has separate pipe ranks sampled with a tremulant on in that sample set:
https://www.milandigitalaudio.com/instruments/baroque/1741-bovenkerk-hinsz/?back=Instruments
Hence the same applies (for all ranks apart from the Vox Humana) as with Mt. Carmel Skinner sample set that you asked about previously in this topic: viewtopic.php?f=13&t=14404
I.e. you need to use the Trem_... attributes in the CODM's Rank entry to define a tremulant for the (un-tremmed) pipe rank samples, in the way covered in the 'Using Hauptwerk’s native tremulant model' section in the CODM user guide (page15 in the current v4.2.1 version).