Just a checks-and-balances question, to which the answer is likely “Yes”:
Are you 100% sure that this is fully unrelated to using an Android 13 base in combination with Sony’s software binaries for Android 12 v2a (i.e. SW_binaries_for_Xperia_Android_12_4.19_v2a_lena). IOW, did you measure power consumption in the same way you do it now when using the old Xperia 10 III motherboard with an Android 13 base (and later with an Android 12 one) in combination with Sony’s software binaries for Android 12 v2a (as you described here in detail)?