HELP NEEDED PLEASE …Could someone please advise me on above post….roofers are coming SATURDAY

I try to avoid any penetration through a roof.

Absolutely install the penetration through the roof as part of the roofing job. This will minimize the risk of leaks.

The duct need not be straight up, it can deviate in the attic so that the external cap or blower is in a good position. Pressure losses in short additional lengths of ducting and modest bends are small relative to the hood baffle pressure loss or imperfect make-up air pressure loss.

The roofers will have to mess with the cap or blower if already in place, but I would ask them which they prefer as they have to guarantee the roof's zero leakage. Typical installation directions from such as Broan/Best/NuTone describe cutting into an already shingled roof. Part of the interface will have to go under shingles, and part will lie over shingles. Your contractor should also have an opinion. But I wouldn't hastily do ducting without having a complete hood system plan and a make-up air system plan.

Yes, all penetrations through roof are done prior to initial roof "felt" or "waterproofing" layer. GCs have plumbers run plumbing vents, mechanical contractors run hood & bath vents when applicable - some thru roof, some through walls. Use the specs to determine duct size & roof jack size. Most inspectors expect these run through the roof deck prior to roof deck nail inspection (called "sheet & shear" or sometimes combined with "frame" inspection)

Of course at this point the hood vent should be selected and ordered, plumbing rough in valves in hand for install, sinks selected to complete cabinet designs for plumbing layout, etc.

Best choice-- vent through a sidewall, no hole in the roof

Second best-- install and flash the vent as part of the roofing process.

Ditto

With a competent tradesperson, either option is feasible. If you do not have the roof vent in-hand now, I would wait and do the install later.