There's absolutely no issues calling s.t() multiple times, as long as you want each of those calls treated as a page view.
Really the only differences between s.t() and s.tl() are as such:
- s.t() calls increment page views while s.tl() calls do not
- s.t() calls collect pageName and pageURL while s.tl() calls do not
- s.t() calls send all defined variables while s.tl() calls only send variables defined in s.linkTrackVars
Based on your business requirements, if you want additional page views to be incremented as they scroll through it, by all means use s.t(). If you want page views to only increment on actual page loads, consider using s.tl() calls.