One solution to the "keep it open at this page" problem is to use weighted cords that are attached to the top-back of such a stand and dangle down over the opened book, one per page, left & right. I'm sure I've seen this on church lecterns and similar thingies used when someone stands and reads to an audience.
I imagine that, to be effective, the cords would need a means to be hung down at a variety of spots along the top edge of the bookstand (for wider & narrower books) with the weights sufficient to keep the cords taught against the inclination of the open book pages to close up again. Perhaps the cords & weights could be dismountable, with a row of attachment points for them along the back-top of the stand. The cords & weights might live in a small drawer at the bottom of the bookstand......
Eshmiel
I imagine that, to be effective, the cords would need a means to be hung down at a variety of spots along the top edge of the bookstand (for wider & narrower books) with the weights sufficient to keep the cords taught against the inclination of the open book pages to close up again. Perhaps the cords & weights could be dismountable, with a row of attachment points for them along the back-top of the stand. The cords & weights might live in a small drawer at the bottom of the bookstand......
Eshmiel