Dryer vent

I have a dryer vent window.

I would like to install a dryer box and have most of the dryer vent pipe concealed behind drywall.

Will it be OK if at the last small section, the dryer vent exits the drywall through a large hole to turn 90 and connect to the vent section in the dryer vent window?

In other words, is it OK for a dryer vent to exit through drywall? I know a furnace vent pipe, for example, requires quite large clearances from flammables. Do the same rules apply to a dryer vent?

No problem here with that. All dryer duct must be metal, no plastic, and anthing in the wall, or anything except a short flex right at the dryer, must be smooth wall..no corrugated.