"But doing a later warp onto the island where you can skip getting a bike and just have to walk a short bit till getting directly to the compound door isnt possible anymore, is it?" never heard of this sorry

should work as soon as you gain control (being in 1st person when starting the heist allows you to have control immediately after the cutscene if you didn't know)

would like to see a video of this happening also

u might be blowing up the c4 too close to the island maybe?

o yeah i meant macro sry, thanks for feedback!

are they used and if so how can i get them

any idea on which agency is the most beneficial for speedrunning?