Install after TMO if you are using the TMO version. It overwrites the TMO roster files and texture files.
If you are using the non TMO version I would guess pretty late in the install order
(Please note I have not made the TMO and non TMO versions yet, but I will be

)
I am not sure about RSRD compatibility yet - I have not looked at the RSRD roster files
Personally I would like to be in port when installing it.
If it was just textures it would probably be fine to enable anytime.
But from reading old threads I have a feeling when you start a patrol it loads all the coming shipping layer, so I do not know what would happen if you then went ahead and overwrote the roster files mid patrol.
This is just a wild assed guess
__________________
--------------------------------------------------
Authority should derive from the consent of the governed, not from the threat of force
If the only tool you have is a hammer, pretty soon everything starts to look like a nail
FOTRS Ultimate
http://www.subsim.com/radioroom/showthread.php?t=226270
The future of SH4 - coming to a PC near you soon