I am curious... did you do the selenium before bleaching or after...? I've been using thiourea dioxide toner to achieve a certain image colour/tonality and 'knock it down' a little with selenium...
To a great extent it depends of the used paper. But in principle Se shifts the hue to a more reddish nuance after thiourea, with a loss at density in the shadows.
SE first protects shadows and middle densities from bleach, in dependence on dilution and toning-time. In extreme-case, only the lights remain accessible for sulphur (thiourea) with what the colour of lights becomes less yellowish but cooler and more reddish then.
For comparison, I could show an example later this evening, if you are interested.
Oh - very much so....! I'd love to see the difference as far as it relates to your practice... it sounds to me as though using the Se beforehand might be more interesting. I've played around with approximate effects simply by partial bleaching... just for 10-20 seconds in my dilution - but of course this yields somewhat inconsistent results. It sounds like selenium might be a nice control to split the tone.
Though I'm not sure if I'd get the (really subtle) blues, greys and greens/yellows that I like if I used Se beforehand... it's a VERY interesting process I've been using for about 8 months now... that I am only just STARTING to understand.