How to minimize SDCentral into sytem tray

Have you tried Component Tray?  It's part of the ODNT subscription and sits in the systray.

Component Tray will alert you when there is a new Object Desktop component available, allows you to launch components directly from it, gives easy access to Stardock Central and online information!

(Note that the screenshot is a bit out of date on the link above.)

I will give it a go when I get my Object Desktop subscription, which shouldn't be far into the future. However, I'd like to see "Minimize to system tray" feature implemented in SDCentral. Keep reading... If you go Tools --> Settings --> General --> AutoUpdate then you'll see that there is a tick box that says "Check for new and updated applications every hour". So, when designing SDCentral, the person who put that option in place obviously expected the application to be running constantly for a number of hours, otherwise this option would have been completely useless. Now that we've established that, I think this puts SDCentral on almost the same plank as iTunes and Windows Live Mail. This is because in the former you can set it to check for new podcasts after a certain period of time and similar with the latter but this time it's with emails. As I'm sure you are perfectly aware that both iTunes and Windows Live Mail have the option of being minimized to system tray when the "Minimize" button is clicked on. I hope I've made a logical argument to include this option into SDCentral. I rest my case...  

depending on what you skinned SDC with... what happens on a double click on the top?

I'm using the Argos premium suite skinned with WindowBlinds (5.51.025).

When I double-click on the top it maximizes to fill the whole screen.

don't have the Argos, not familiar with it... I do know per pixel skins can act different... WB config in the overrides section, does setting the right click or double click action to minimize to tray work?

Used a number of per pixel skins that never caused a glitch. However, this does not change the main point that there should be an option in settings that will allow minimize to sys tray upon clicking the respective button in the top right corner

wb config > override default settings > check box under title bar settings "windows should minimize to the system tray instead of the taskbar" = doesn't work?

The thing is, I don't want to do this because it would mean that for every title bar I'd double-click it would go into system tray, which is not right. It's natural to double-click the title bar to maximize the window and that's the way it should stay.

I also don't see why I have to do it. In my opinion, I've made a very strong argument to have that feature included into SDCentral's settings ASAP.

A strong argument does not make it a priority. 

(But it is a good argument )

I'm glad that it is a good argument for you. I'm still puzzled and don't understand why it wasn't included when Stardock's magicians designed SDCentral...