Most agencies I've worked in use the 80-20 rule for ICs. 80% of hours towards client deliverables. 20% towards learning, upskilling, etc.
For managers/supervisors, it depends on things like the cost gap between them and ICs, how many ICs you have, agency expectations for them to teach/train ICs and/or contribute to internal projects. 80-20 could work, but often I've seen it range from 70-30 to 60-40.