Hi there @werny,
Great question in relation to using AdSense within Site Kit, but without Auto ads. You can do this, however you would need to insert your single ad unit code manually, or via a third party plugin. If using a third party ads specific plugin, such as Advanced Ads or Ad Inserter you can use the same single ad unit across certain sports, to your liking.
After placing your single ad unit code on your site you can revisit your Site Kit AdSense settings and ensure the plugin has not placed AdSense code on your site, as this refers to the Auto ads snippet. You’ll find the settings under “Site Kit > Settings > Connected Services > AdSense > Edit“, all from within your WordPress dashboard.
Once you have the above complete you can view your AdSense data within the Site Kit dashboards, without having used the plugin to place your AdSense code. As long as you’ve placed your single ad unit code via other means ads will appear only where you’ve placed them, either manually or via another plugin.
Note that you may also wish to confirm that Auto ads are off at AdSense level. Without doing so it’s possible for Auto ads to appear on your site via this setting, with only single ad unit code placed on your site (Ads > Overview > Edit > Auto ads).
Let me know if you have any questions with the above.