Here are a couple of things about RC 300 that I found unintutive that deserve an FAQ
How can I record on a track set to One Shot?
you can't. You need to change the track properties to be something other than One Shot and then you can record / overdub to your hearts content.
Most probably you want to do One shot because you want the track to play out of sync with other tracks. ie. Have a different length and start as per your demand. In such cases I prefer to turn "Loop Sync" off and keep "Temp Sync" on. This way you can use the track as One Shot where you have to stop it yourself.
The drums/precussion switches off when I stop playback of the last loop
That is unfortunate. However you can record a dummy background loop if you MUST the beat playing all the time.
How can I record on a track set to One Shot?
you can't. You need to change the track properties to be something other than One Shot and then you can record / overdub to your hearts content.
Most probably you want to do One shot because you want the track to play out of sync with other tracks. ie. Have a different length and start as per your demand. In such cases I prefer to turn "Loop Sync" off and keep "Temp Sync" on. This way you can use the track as One Shot where you have to stop it yourself.
The drums/precussion switches off when I stop playback of the last loop
That is unfortunate. However you can record a dummy background loop if you MUST the beat playing all the time.