>>64505957
Nearly all Chi-Hes were converted into Chi-Nus. Next they were to be upgraded with the longer gun into Chi-Nu II.

Chi-Se could be viable for this era. Apparently it wasn't ever meant to be build, but only planned to upkeep skills. Details about it are vague, providing some artistic leeway. It could even have interleaved suspension, which was considered for Chi-Ri.