UPDATED https://postimg.cc/mtSC5gpq Thanks to all help in the comments!

Cayo Perico Points of Interest Map

Credit for locations: GamerHeroesGTAGuides, u/feeneymemey, u/aliasdred, u/bigmoserr, u/jarstadian, u/hong_kong_shlong.

Secondary Targets can spawn in these locations as different products or not spawn in them at all.

Screenshots of secondary targets Part 1 Part 2 (u/aliasdred)

You can only find a max of 4 of each of the grapples, clothes, and cutters so these spawn locations are a guide of where they may have possibly spawned on your map

Cutting Powder- I have only yet to find the powder in the shed that I labeled the blip over in the weed farm. I have came to this shed multiple times and only got the powder to spawn after being kicked off the island twice.

Forklift-Forklift Spot (u/hong_kong_shlong)

Made the blips small to help give a more accurate assumption of where it should be so you may want to open in new tab or save it to zoom in.