Mod added SMG tiers will still work, they just don't get the infiltration or mobility bonuses. So there's not much point in using them. In my game for instance my laser and coil SMGs are basically just unused placeholders but the conventional, mag, and plasma SMGs get infiltration and mobility bonuses.

This only has config for the three vanilla tiers of SMG, right?

For "[WOTC] Renamed SMGs Mod" ini edit.

XComInfiltration.ini

"SMG_CV" to "Vee_SMG_CV"
"SMG_MG" to "Vee_SMG_MG"
"SMG_BM" to "Vee_SMG_BM"
--------------------------------------------------------
XComStrategyTuning.ini

"SMG_CV" to "Vee_SMG_CV"
"SMG_MG" to "Vee_SMG_MG"
"SMG_BM" to "Vee_SMG_BM"

"SMG_MG_Schematic" to "Vee_SMG_MG_Schematic"
"SMG_BM_Schematic" to "Vee_SMG_BM_Schematic"
------------------------------------------------------------
XComWeaponTuning.ini

[SMG_MG X2WeaponTemplate] to [Vee_SMG_MG X2WeaponTemplate]
[SMG_MG_Diff_3 X2WeaponTemplate] to [Vee_SMG_MG_Diff_3 X2WeaponTemplate]
[SMG_BM X2WeaponTemplate] to [Vee_SMG_BM X2WeaponTemplate]
[SMG_BM_Diff_3 X2WeaponTemplate] to [Vee_SMG_BM_Diff_3 X2WeaponTemplate]