I did a quick search on the forums, and it appears this has been discussed with limited interest a few years ago. The reason I bring it up now is because Robert McKeon Aloe (espressofun on IG) stated that he has data / results from spraying the puck prior to pulling a shot and plans to publish in the coming month. It got me interested and I recently experimented with spraying before I pull a shot.

My technique: prep the puck as normal, add a paper filter on top of the puck, spray the paper filter with my spray bottle until it is evenly wetted. Insert and pull the shot. I have been happy with the results. With certain beans I'll sometimes have channeling with my normal prep method, but when spraying the puck I've not had the same issue. Now this could be due to the spray, but it could also be that when I plan to spray a puck, I'm taking more time on the overall puck prep, including WDT. I have not pulled enough shots or experiemented enough to form an opinion.

I'm wondering if anyone here as more data or experience with this technique.

Stéphane Ribes was one of the first to explore this. Here's a thread from a couple of years ago on H-B Spraying Espresso Pucks

All of this was before the use of sintered mesh or perforated puck-top screens became popular.

Lot's of old topics on this interesting and controversial topic. But it's actually a hard topic to search on this site because "spraying" and "misting" etc brings up so many unrelated threads related to poor extractions that spray or channel horribly. I couldn't even find the good one from a long time ago. I searched "lecithin" when folks were talking about using diluted lethicin in a spray bottle to improve solubility of the top of the puck. Never seemed to gain any traction. It probably didn't really do much. Here's one that I did find though.

Spraying mineral solutions on to pucks-a facile way to contour water minerals on a per cup basis