SCS: Should Debuff Spells Ignore Immunity to Spell Level?

Liches are only affected by spells from level 6 or higher. Rakshasas are only affected by spells from level 8 or higher. SCS made a sensible decision to make Breach work even against these monsters. This exception doesn't extend to other debuffing spells like Spell Thrust, Secret Word and so on. Don't you think this should change?

I vote yes. My reasoning is that, e.g., Minor Globe of Invulnerability is an outer shield and therefore it shouldn't benefit from its caster's immunity to level 3 spells. Spell Thrust should take it down.

How does it work in Pen and Paper rules?

Thanks to everybody for creating this great game and to @DavidW for SCS!