Because the rules for nexus are so complicated from US state to state, it's difficult to figure out which states my company currently needs a sales tax license for. What is the recommended strategy for selling to states where the company has nexus but does not yet have a sales tax license? Should we block sales to states like Rhode Island that seem to require a sales tax license from day 1? (Does Shopify provide tools for blocking sales to specific states?) Conversely, should we apply for a sales tax license in every state regardless of how many sales are made to that state, even if we have made 0 sales? Or, is there a middle ground for navigating this devilishly tricky conundrum? Any thoughts would be appreciated, thanks!