[ATUCIT_Fox]

Basically, the script is a bit longer than most, because switching from smoke grenades to the last used weapon brings you to your normal grenades...This is what I have though:

(I use DEL and PGDN to switch to the two types of grenades, and use arrows to walk...)
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alias w5 "wait; wait; wait; wait; wait"
alias w25 "w5; w5; w5; w5; w5"
alias w125 "w25; w25; w25; w25; w25"
alias [weapon]gren "useweaponclass grenade; bind PGDN backto[weapon]; bind DEL [weapon]grensmoke"
alias [weapon]smoke "useweaponclass grenade; w125; useweaponclass grenade; bind PGDN backto[weapon]; bind DEL [weapon]smokegren"
alias [weapon]grensmoke "useweaponclass grenade; bind DEL [weapon]smokegren"
alias [weapon]smokegren "useweaponclass grenade; bind DEL [weapon]grensmoke"
alias backto[weapon] "useweaponclass [weapon]; bind PGDN [weapon]gren; bind PGDN [weapon]smoke"
bind [weaponkey] "backto[weapon]"
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where [weapon] = {rifle, pistol, smg, mg, heavy} and [weaponkey] is the key where you want to assign the main weapon to.
This script needs initializing to get the main weapon right, and uses DEL to go to smoke grenades and PGDN to normal grenades. Once you have anything other than your main weapon in hand, PGDN is used to switch back to the main weapon, and DEL cycles through the grenades.

If you want two scripts that more resemble the one you already have:

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//Wait
alias w5 "wait; wait; wait; wait; wait"
alias w25 "w5; w5; w5; w5; w5"
alias w50 "w25; w25"
alias w125 "w25; w25; w25; w25; w25"
//Normal grenades
alias +grenade[weapon] "useweaponclass grenade; wait"
alias -grenade[weapon] "w50; useweaponclass [weapon]"
//Smoke grenades
alias +smoke[weapon] "useweaponclass grenade; w125; useweaponclass grenade"
alias -smoke[weapon] "w50; useweaponclass [weapon]"
//Other
alias setfor[weapon] "bind HOME +grenade[weapon]; bind END +smoke[weapon]"

bind KP_2 "setforrifle"
bind KP_3 "setforsmg"
bind KP_4 "setformg"
bind KP_6 "setforheavy"
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After using these scripts for some time, I have decided to go to a very simple configuration, which is better imo:

alias backtorifle "useweaponclass rifle"
alias backtosmg "useweaponclass smg"
alias backtomg "useweaponclass mg"
alias backtoheavy "useweaponclass heavy"

bind DEL "useweaponclass grenade"
bind KP_2 "backtorifle; bind PGDN backtorifle"
bind KP_3 "backtosmg; bind PGDN backtosmg"
bind KP_4 "backtomg; bind PGDN backtoMG"
bind KP_6 "backtoheavy; bind PGDN backtoheavy"
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This script has no direct access to the smoke grenades, but works faster bacause it has no "wait" inside the script: pressing DEL twice is faster than using the w125 (which needs to be that long to ensure it works under all conditions)

Enjoy
Fox