Hmm, as long as you don't open the code in the mIRC editor it won't break your indendation style... but surely you use an editor decent enough that it allows you to have different indendation styles for different languages (
www.textpad.com)? If all you want is a better automatic reload a small addon, like the one included in my TextPad mIRC Addons (come.to/vague), which does reloading transparently (i.e. without bothering you every time), will work decently. It's completly editor agnostic, in no way specifically tied to TextPad (Which the other stuff included with that file, macros and syntax highlighting files, are).
Coding with a decent editor, with decent syntax highlighting and all the editor features of such a tool (projects, advanced search'n'replace, ...) is, to a lot of people, preferable to using mIRC's very limited default editor. Your mileage might vary, as they say =)
