Do I understand correctly from the forums that 1. CBSubs has no add-to-cart function that would allow us to bundle merchandise sales;

Correct, it's a subscription manager and not a digital store. For that you should use VirtueMart.

and that 2. That functionality is in development and coming soon?

We've discussed it internally and sometime in the future we'd like a full shopping cart, but it's not a priority at this time.

We are currently using CBSubs, but trying to decide whether to find another solution that will enable this capability on one of our sites.

Wouldn't wait on such a feature. The best digital store solution for Joomla is VirtueMart and with VM2 having released it's probably the only solution. CBSubs can also interact with VM1/2. CB Auto Actions can as well. This allows you to for example give users discounts for subscribing to a CBSubs plan by placing them in say a 10% discounted VirtueMart shopper group.

I understand, but just for subscription management alone it has taken years to develop. Trying to add a complete shopping cart frontend is another very large task on its own. We'd like to have such a feature, but ideally we need what CBSubs was specifically designed for to be where we feel it should be. This isn't saying we're not going to have a shopping cart is in reality it's half-implemented as what we refer to as "baskets". We definitely have plans for such a feature and have had numerous internal discussions regarding it. I just don't recommend waiting for such a feature as I can't tell you even remotely if/when it'd be available.