Please allow us to double click within the Marker track to add a new Marker.
(And auto select its text to let us type in the name without extra clicks)
Right now you can only add a marker by using the keyboard, which means changing input tools and remembering shortcuts. Keyboard shortcuts should always be optional, not mandatory.
Almost everything in Studio One is super-intuitive - not being able to add a Marker this way is one of the few things that is a PITA and should be a relatively easy addition.