{7, 0, 100} I'm guessing that first number is default value, while the other 2 are min/max values allowed.
I have it set up like this:

MIN_DELAY_ENEMY_REINFORCEMENTS = 0
RND_DELAY_ENEMY_REINFORCEMENTS = 0
MIN_ENTER_ENEMY_REINFORCEMENTS = 64
RND_ENTER_ENEMY_REINFORCEMENTS = 64
MIN_DELAY_MILITIA_REINFORCEMENTS = 0
RND_DELAY_MILITIA_REINFORCEMENTS = 0
MIN_ENTER_MILITIA_REINFORCEMENTS = 64
RND_ENTER_MILITIA_REINFORCEMENTS = 64

When I used this value reinforcements came as they used to, as soon as they were called. It was counterattack event in Chitzena so about 96 enemies appeared and no stealth since it was day attack.

I'm guessing the problem is that default values are 7 turns min delay for enemy forces and 8 turns added random value to that so it can take up to 15 turns for enemy forces to appear. Similar for for militia where min is 10 and and adds random 10 value which can make them come after 20 turns.

If you set gGameExternalOptions.sMinDelayEnemyReinforcements = iniReader.ReadInteger("Strategic Gameplay Settings", "MIN_DELAY_ENEMY_REINFORCEMENTS", 0, 0, 100
and
gGameExternalOptions.sMinDelayMilitiaReinforcements = iniReader.ReadInteger("Strategic Gameplay Settings", "MIN_DELAY_MILITIA_REINFORCEMENTS", 0, 0, 100)
it should work as it used to in vanilla.

Btw, values of 7 or even 10 turns min delay are a bit excessive since by that time most of the fights are almost resolved. Kindda think it's best to have them set as they are in vanilla and have modders and players play with them.