I think this would be an excellent idea, adding this mode would allow channel owners to add rights to users based on nick!ident@host masking.
Here's what the flag's mode on ChanServ looks like in ATHEME
04:03:49 -ChanServ- ***** ChanServ Help *****
04:03:49 -ChanServ- Help for FLAGS:
04:03:49 -ChanServ-
04:03:49 -ChanServ- The FLAGS command allows for the granting/removal of channel
04:03:49 -ChanServ- privileges on a more specific, non-generalized level. It
04:03:49 -ChanServ- supports both nicknames and hostmasks as targets.
04:03:49 -ChanServ-
04:03:49 -ChanServ- When only the channel argument is given, a listing of
04:03:49 -ChanServ- permissions granted to users will be displayed.
04:03:49 -ChanServ-
04:03:49 -ChanServ- Syntax: FLAGS <#channel>
04:03:49 -ChanServ-
04:03:49 -ChanServ- Otherwise, an access entry is modified. A modification may be
04:03:49 -ChanServ- specified by a template name (changes the access to the
04:03:49 -ChanServ- template) or a flags change (starts with + or -). See the
04:03:49 -ChanServ- TEMPLATE help entry for more information about templates.
04:03:49 -ChanServ-
04:03:49 -ChanServ- If you are not a founder, you may only manipulate flags you
04:03:49 -ChanServ- have yourself, and may not edit users that have flags you
04:03:49 -ChanServ- don't have. For this purpose, +v grants +V, +h grants +H,
04:03:49 -ChanServ- +o grants +O and +r grants +b.
04:03:49 -ChanServ-
04:03:49 -ChanServ- If you do not have +f you may still remove your own access
04:03:49 -ChanServ- with -*.
04:03:49 -ChanServ-
04:03:49 -ChanServ- Syntax: FLAGS <#channel> [nickname|hostmask template]
04:03:49 -ChanServ- Syntax: FLAGS <#channel> [nickname|hostmask flag_changes]
04:03:49 -ChanServ-
04:03:49 -ChanServ- Permissions:
04:03:49 -ChanServ- +v - Enables use of the voice/devoice commands.
04:03:49 -ChanServ- +V - Enables automatic voice.
04:03:49 -ChanServ- +h - Enables use of the halfop/dehalfop commands.
04:03:49 -ChanServ- +H - Enables automatic halfop.
04:03:49 -ChanServ- +o - Enables use of the op/deop commands.
04:03:49 -ChanServ- +O - Enables automatic op.
04:03:49 -ChanServ- +a - Enables use of the protect/deprotect commands.
04:03:49 -ChanServ- +q - Enables use of the owner/deowner commands.
04:03:49 -ChanServ- +s - Enables use of the set command.
04:03:49 -ChanServ- +i - Enables use of the invite and getkey commands.
04:03:49 -ChanServ- +r - Enables use of the kick, kickban, ban and unban commands.
04:03:49 -ChanServ- +R - Enables use of the recover and clear commands.
04:03:49 -ChanServ- +f - Enables modification of channel access lists.
04:03:49 -ChanServ- +t - Enables use of the topic and topicappend commands.
04:03:49 -ChanServ- +A - Enables viewing of channel access lists.
04:03:49 -ChanServ- +F - Grants full founder access.
04:03:49 -ChanServ- +b - Enables automatic kickban.
04:03:49 -ChanServ-
04:03:49 -ChanServ- The special permission +* adds all permissions except +b and +F.
04:03:49 -ChanServ- The special permission -* removes all permissions including +b and +F.
04:03:49 -ChanServ-
04:03:49 -ChanServ- Examples:
04:03:49 -ChanServ- /msg ChanServ FLAGS #foo
04:03:49 -ChanServ- /msg ChanServ FLAGS #foo foo!*@bar.com VOP
04:03:49 -ChanServ- /msg ChanServ FLAGS #foo foo!*@bar.com -V+oO
04:03:49 -ChanServ- /msg ChanServ FLAGS #foo foo!*@bar.com -*
04:03:49 -ChanServ- /msg ChanServ FLAGS #foo foo +oOtsi
04:03:49 -ChanServ- /msg ChanServ FLAGS #foo TroubleUser!*@*.troubleisp.net +b
04:03:49 -ChanServ- ***** End of Help *****