Does Sheet Margin/Plate Number Add Value?

Excellent advice!
Simple to do, and blends well, adds flavour to an otherwise run of the mill,
"in order" sequencing.

Believe it or not, this also adds value, as I have just learnt the term "salting"
One adds intrigue and desire by adding subsidiary items.

I have spoken to philatelic gatherings on a number of occasions with the opening quote attributed to the great experimentalist, Ernest Rutherford, to wit "All science is either physics or stamp-collecting." From there I briefly elaborate on the science of botany, one feature of which is the classification of plants into family, genus, and species. Physics on the other hand deals in experiments in order to develop the laws of nature and the interactions between objects. Similarly, I think that stamp collectors can be divided into at least two types: (1) those who are interested in obtaining one stamp for each space provided in an album (analogous to the botanical classification of family, genus, and species) and (2) those who collect multiples, plate blocks, covers, special cancels, essays, proofs, etc, as a means to understand the use and relationships among stamps. I am not saying that one type of collector is better than the other, just that there are at least two types of collectors.