You have to give the correct path when remapping, else it may break. I have manually remapped one on the S3 link from the sample output you provided earlier and it works.
An image hosted in the bucket:
The same image hosted in your local server:
You may open the image in a new tab to see the links of both the above image. So I assume this will work.
./launcher enter app
discourse remap //bxyzbucket1.s3.dualstack.ap-south-1.amazonaws.com/uploads/ /uploads/default/
discourse remap //bhdisco.s3.dualstack.ap-south-1.amazonaws.com/uploads/ /uploads/default/
rake posts:rebake