Whoa! 30 minutes at least but preferably 45? On 15 employees? That's 8-11 hours every week spent doing 1:1s. If you work 40 hour week, that's between a fifth and a quarter of your time spent just doing 1:1s and not doing anything else, like actually solving issues!

Had a manager like that. Always busy, always in a rush... and when you looked at what he actually accomplished for his employees or for higher ups in the chain, it turned out to be very little. His main job seemed to be status updates of the excel sheets. All talk, no work. In the end.