Light is a bit tricky, and the indication I use is the colour of the leaves, I would give the plant as much light as it can support, and the leaves should be an olive green colour.
There is also the distance from the light source, and the timing factor. The light level decreases away from a window even if it is facing west, so closer to the window is the best location. In terms of timing you should increase light level when the pseudobulb is maturing, and this should normally coincide with the cooler months, hence the lower temperature and reduced watering. All of this should happen at the same time, although light is the most important factor.
I can’t tell you with certainty whether an old pseudobulb can flower, funny cause I had an onc. spacelatum for years when I was living in the tropics that flowered every year, and I never payed attention to this. I hope someone can help