Hi there,
My name is Caitlin and I work on the product team here at HubSpot. If you add Tasks to your Sequences and have your Sequence set to execute on weekdays only, the tasks should also follow this rule. Are you seeing that this is not the case?
For example, in the screenshot below, I have each step of my Sequence to execute 1 day after the previous step and I have it set to send follow-ups on weekdays only. On the right, you can see that Step 3 is a Task set to execute 1 day after the email before it, which would be a Saturday in this case (since Step 2 is scheduled for Friday), but with the weekday setting enabled, it is pushed to Monday.
Best,
Caitlin