Is possible to add text overlay on gpu?
e.g:

local buffer = gpu.allocateBuffer()
gpu.set(1, 1, “A”)
gpu.setActiveBuffer(buffer)
gpu.set(1, 1, "_")
gpu.setActiveBuffer(0)
gpu.attachBuffer(0, buffer)

Draw a cursor on character 'A'

At this point you may want to have a 'real' graphical screen in OC, as text overlapping would allow the same kind of things as a graphicam screen. Also, on your example, i would not make use of allocateBuffer, but rayher use an additional function like setTransparency or something like that...