General reply.
While it would probably benefit some people (or least make it easier for them) if the feature is implemented, as pointed out before it is already possible to use the pin to taskbar feature to achieve the goal already. So adding some option to the mIRC might not be all that important (especially considering that there are just too many different possiblilities exactly how this should be implemented).
As far as "power users" go it is not too difficult to implement this feature via scripting.
Maybe I approach this question wrong but given the set of tools we have right now I feel that we have quite a lot of "power" to implement the "run only one instance" exactly the way each scripter would prefer.
Whether it is to ensure that only one mirc executable runs at any given moment or whether we want to ensure that only one process per mirc.ini is running.
While mIRC is essentially a chat application we still cannot ignore the quite powerful and "FLEXIBLE" scripting engine we are given to work with, so you can extend the program and make it behave exactly the way YOU want it to behave.
---
I faced the situation where I needed to make sure that user wont start two instances of a mIRC bot twice and the road I went was to make sure that user will not be running two instances of mirc that use same mirc.ini.
While there are possibly other ways to reach the same goal my solution was simply utilizing $mircini and communicating between clients via DDE. Which in just few lines of script let me achieve the exact goal.
When I start second instance of the bot it will simply close and bring the already running instance to the foreground.
---
mIRC is a program that can be run simultaneously from multiple directories and that is as far as I can see "by design".
So if you want to have only one instance active then install mIRC to only one directory and utilize pin-to-taskbar feature. Seems like quite simple solution to me.
If you have multiple mIRC executables in various directories then you should already be considered "advanced user" and you are given scripting engine to deal with different scenarios at your own discretion.
