Hi Ken,
It's difficult to say whether one strategy will produce a lower bounce rate than the other. Really, to avoid bounces, ClickDimensions strongly suggests using permission-based email marketing as the foundation of your marketing strategy. Other practices, such as maintaining good marketing lists, using Subscription Management, setting up an SPF record, etc. are also recommended.
Something to also keep in mind: the nature of the bounces is something to consider. ClickDimensions distinguishes between hard bounces and soft bounces. Both of these combined will make up the percentage of bounces associated with your particular Email Send. A soft bounce generally indicates a less permanent issue (the recipient's inbox is full, for example), whereas a hard bounce is either a DNS failure, invalid recipient, or generic bounce; no receipt, which indicate a more permanent issue. ClickDimensions allows 4 soft bounces to occur within a rolling 3-month period, on the 4th soft bounce it will become a hard bounce, and the recipient would be blocked from receiving emails sent from you using ClickDimensions.
Unfortunately, I do not have any hard rules when it comes to timing for Email Sends; there are so many variables to consider: your audience, where they are located in the world, your business market, trends, etc. though we do have some suggestions to consider what will work best for your marketing strategy:
Variations on Resending Emails to Non-Openers