I have a form that leads will need to fill out multiple times with different field values each time (other than name and email). Is there any way to save each submission without overwriting field values of the previous one?
The question is what you mean by "saved".
The most typical way to keep a history of responses is a History Field: as fields change, write them to a Textarea field, together with a timestamp, that's designed to hold the person's earlier values.
What do you need to do with the old values that wouldn't be solved by the History Field model?