Is your feature request related to a problem? Please describe.

Currently:

For a given block sequence, only one type of index file is supported. If new index 
files are needed (different `index-file-size` or `index-attribute`), the entire 
block sequence must be uploaded from the beginning.

Describe the solution you'd like

Be able to create index files with different index-attribute or index-file-size based on the already uploaded block sequence.

Describe alternatives you've considered

Leave it as is.