Unable to add Immovable modifier to shield via Etch Rune mechanic

[R3ality]

I have an Etched Runestone with a previously extracted Immovable modifier. But I am unable to use the Enchantment Table to etch this modifier onto a shield.

Regardless of which existing modifier is selected for replacing, the "Select Enchantment to overwrite" does not list the Immovable modifier a possible option.

[R3ality]

After further investigation I realize now that this may be by design as the Immovable modifier is limited to non-parry shield types only (i.e. Tower Shield).

Leaving this report open as a suggestion/discussion. With going through the trouble of extracting a modifier (with material cost + loss of the item) and etching it (with material cost + reusing an existing modifier slot) I feel like there should be a way to achive this combination of a parry shield + Immovable modifier.

Perhaps a separate config option to allow "illegal" modifier combinations?