Ok, the reason #9 didn't make any sense to me was because I had it wrong... sorta. (It's 1:43pm on 2/1/2005 for those of you keeping track!!)
original post here: http://www.geekswithblogs.net/cwilliams/archive/2005/02/01/21668.aspx
You can control the max input on an edit field, simply by sizing the edit field to the size you want. But... let's be honest this isn't always (ever?) practical. And if you want any uniformtity in the appearance of your UI, it's just not an option.
You can set a flag via the property sheet to allow text to go beyond the size of the edit field, but that's not on by default. (and that seems backwards to me)
If you want to limit the amount of input to less than the visual size of the field, you have to hack the dialog definitions in the InstallShield source files. Two of the InstallShield KB articles tell you how to do this, although they also caution against it. (If you're interested, they are #Q101169 & #Q101338 on the InstallShield.com site)
This really should be something you can set via the property sheet.