So instead of filing a feature suggestion, you should of filed a bug report about the desync so we could of examined your code...
But as far as /timers are concerned, if you need pin point accuracy then don't use mIRC and mSL for projects. As plain and simple as it gets, mIRC is an IRC client and IRC isn't a time critical environment (spare me the TS debate), nor developed on that model. So why should the clients move towards that direction?
To solve the desync issue however, I'd write my own time scheduler using an Object Oriented model and choose whatever format I wanted for representing the date/time/millisecond reference, and perhaps use a pre-fetch mechanism that schedules an exclusive check a minute before it's suppose to trigger just to verify its on time, then make any corrections and schedule yet another exclusive timer.
