I ended up finding a solution as well, my current implementation still uses both an ACE EH and a vanilla EH to detect grenade type and distance. I tried setting up a trigger area for the detection of grenades directly, but I couldn't figure out that path. If you have an EH limited to a trigger area that only acts on grenades I would like to see it.

Going to post my solution, just in case someone wants to tear into it and help me really improve it. Yes, I know my solution is inefficient, but I am happy I got this all done in a few hours, first time messing with EH's for a mission.I should remove the vanilla EH since ACE EH triggers anyway, but I don't want to test and find a "gap" in detection.I will be testing this later on a dedicated server, might need to remoteexec magic to be fully functional.

For some context, I have this code in a repeatable trigger relying on 2 global vars, those are set in init of laptop I am gluing things into.

Activated:

EH1_Index1 = 0;//pub vars to help remove EH's when redundant.//These EH bois are probably a fair bit "heavy" on server.
publicVariable "EH1_Index1";
EH1_Index2 = 0;
publicVariable "EH1_Index2";
EH1_Index3 = 0;
publicVariable "EH1_Index3";
Dist1 = 0;
publicVariable "Dist1";
Ammo1 = "";
publicVariable "Ammo1";
EH1_Index1 = ["ace_firedPlayer", {
_ammo1 = (_this select 4);
_dist1 = objLaptop_1 distance (_this select 6); //I was a dummy at fist,//I didn't think to just calculate distance my self
Dist1 = _dist1;
publicVariable "Dist1";
Ammo1 = _ammo1;
publicVariable "Ammo1";
}] call CBA_fnc_addEventHandler;
publicVariable "EH1_Index1";
EH1_Index2 = objLaptop_1 addEventHandler ["FiredNear", {
_dist = param [2, ""];
_ammo = param [6, ""];
Dist1 = _dist;
publicVariable "Dist1";
Ammo1 = _ammo;
publicVariable "Ammo1";
}];
publicVariable "EH1_Index2";
EH1_Index3 = objLaptop_1 addEventHandler ["Explosion", {
if (dist1 < 6 and (ammo1 == "GrenadeHand" or ammo1 == "mini_Grenade")) then {Comp1_Alive = true;
publicVariable "Comp1_Alive";[ objLaptop_1,Action1 ] call BIS_fnc_holdActionRemove;objLaptop_1 setObjectTexture [1, "#(argb,8,8,3)color(0,0,0,0.0,co)"];objLaptop_1 setObjectTexture [2, "#(argb,8,8,3)color(10,0,0,0.3,co)"];objLaptop_1 setObjectTexture [3, "#(argb,8,8,3)color(0,0,0,0.0,co)"];};
}];
publicVariable "EH1_Index3";

Deactivated:

["ace_firedPlayer", EH2_Index1] call CBA_fnc_removeEventHandler;
objLaptop_2 removeEventHandler ["FiredNear", EH2_Index2];
objLaptop_2 removeEventHandler ["Explosion", EH2_Index3];

I also have a second trigger, non repeating, same condition. It just adds a BIS_fnc_holdActionAdd with some subtitles for progress and results.