Did you know you can create pagination for <category tag ?
For example
List categories
<category num=1-20 adjust_num_to_page=true>
<!--CATEGORY_NAME-->
</category>
And add pagination
<category type=pagination num=1-20 adjust_num_to_page=true>
<!--PAGE_NUM--> ...
</category>
<category type=pagination
<category type=pagination
Don't forget to run script update