Using the Sundberg-Cooper rheology, we apply several improvements to the tidal evolution of short-period, rocky exoplanets and the early history of Pluto-Charon under the simplifying assumption of homogeneous bodies. By including higher-order eccentricity terms (up to and including e20), we find divergences from the traditionally used e2 truncation starting around e = 0.1. Order-of magnitude-differences begin to occur for e > 0.5. Critically, higher-order eccentricity terms activate additional, spin-orbit resonances. Worlds experiencing non-synchronous rotation can fall into and out of these resonances, altering their long-term evolution. Tracking the dual-body dissipation within Pluto and Charon leads to faster evolution and dramatically different orbital outcomes compared to a single body approach. Based on our findings, we recommend future tidal studies on worlds with an eccentricity greater than around 0.3 take into account additional eccentricity terms beyond e2. This threshold should be lowered to e > 0.1 if non-synchronous rotation or non-zero obliquity is under consideration. Due to the poor convergence of the eccentricity functions, studies on worlds that may experience very high eccentricity (greater than about 0.5) should include terms with quite high powers of eccentricity. Finally, the assumption that short-period, solid-body exoplanets with eccentricity greater than around 0.1 are tidally locked in their 1:1 spin-orbit resonance should be examined on a case-by-case basis. Higher-order spin-orbit resonances can exist even at these relatively modest eccentricities, while other studies have found such resonances can significantly alter stellar-driven climate.