You can put a roof cap over the chimney to vent the smoke as long as you leave a gap for the smoke to exit. This screen shot shows my main lodge on my main save. You can see the
chimneys over the smelter, kiln and blast furnace each chimey has a cap on it. This kind of set up lets the smoke out and keeps the weather out at the same time.
https://steamcommunity.com/sharedfiles/filedetails/?id=2861752379

If you don't want to do the whole chimney cap thing you can use this mod. https://www.nexusmods.com/valheim/mods/1834

It lets the smoke out but not the rain in.

Recently I have moved away from making chimneys having figured out a roof design that imitates how vikings and other ancient peoples vented smoke from their hearth fires. I simply raise a portion of my roof which creates a gap through which smoke can vent. The heat from the fire source creates a chimney effect, pushing smoke upwards towards the roof. As long as there is enough of a gap in the roof all the smoke will vent.

https://steamcommunity.com/sharedfiles/filedetails/?id=2874976444

The building in the left foreground demonstrates how to adequately vent buildings with internal fire sources. Notice the central raised portion of the roof. This works for everything from hanging braziers to central hearths.

Yes but they will also block the smoke.