Yes, this is possible.
You can schedule a Flow to send reminder emails if the client has not yet completed and submitted the account details/contact details/lead details form.
The Flow can check whether an Intermediate record ("Account Update" for Account Form, "Contact Update" for Contact Form, and "Lead Update" for Leads) has been created under the related Account/Contact/Lead. If no record exists, the reminder email will be automatically sent to the client.