Is there a tradeoff between lens thickness and chromatic aberration? if you opt for higher index (more thin), the lower the abbe value tends to be ?

Abbe value is the: Refractive efficiency of lens. Lens with high Abbe: disperse light less: less chromatic aberration. High index materials produce lower Abbe hence more chromatic aberration. Abbe values are inversely proportional to the degree of chromatic aberration. High index lenses are thinner and have more chromatic aberration. Yes it's a trade off.