Assign main texture property via the BlendModeEffect

SetTextureProperty.cs

using BlendModes;
using UnityEngine;

[RequireComponent(typeof(BlendModeEffect))]
public class SetTextureProperty : MonoBehaviour
{
    public Texture2D Texture;

    [ContextMenu("Set Texture")]
    public void SetTexture ()
    {
        var blendModeEffect = GetComponent<BlendModeEffect>();
        blendModeEffect.GetComponentExtension<ComponentExtension>().GetShaderProperty("_MainTex").SetValue(Texture);
        blendModeEffect.SetMaterialDirty();
    }
}