I would find it useful to be able to make plain links between logseq blocks and pdf locations. This is kind of doable today with highlight/region but it would be more clean I think to have this possiblity directly. This is usable if you want to map a pdf but not using directly words from the pdf (like argument-1, argument-2, …)
I would imagine a mouse drag from an arbitary location in the pdf with a line to a block in logseq (and opposite way). Some small symbol could indicate the location in the pdf and the “PXX” symbol in the block could indicate there is a link.
It would likely be expected to be able to delete the link both from the block and in the pdf side.
Regards