I tried this on DODS & had the following error:
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2: SourceMod error session started
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2: Info (map "dod_donner") (file "errors_20100803.log")
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2: [SM] Native "HookConVarChange" reported: Invalid convar handle 0 (error 4)
L 08/03/2010 - 19:16
2: [SM] Displaying call stack trace for plugin "improved-randomizer.smx":
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2: [SM] [0] Line 328, c:\Development\sourcemod\Sourcemod\TestPlugin \improved-randomizer.sp::OnPluginStart()
Looks like it has potential.