@1olbull has posted several times in the past regarding the handling improvements when using a smaller front and larger rear tire on the older Rockets. Many of us have confirmed his posts. The only issue you have to consider is related to how much difference you can have between the front and rear related to stock. Too much could affect your ABS. 1/2 inch larger in the rear and 1/2 inch smaller in front shouldn't trigger an ABS fault. 1olbull did a fair amount of research on this. Read this post from 2020 specifically post 97 related to percentage differences.
Best Tire Size for Handling When it comes to tires and sizes, he's the man...