Can't improvise Rograkh (with commander tax) with Inspiring Statuary

[copperfield42]

If I'm tap out I can't improvise [[Rograkh, Son of Rohgahh]] that have a commander tax with [[Inspiring Statuary]], I feel that you should be able to because it only needs to pay generic mana and I was unable to find evidence of the contrary.

[github-actions]

Rograkh, Son of Rohgahh - (Gatherer) (Scryfall) (EDHREC)

{0}
Legendary Creature — Kobold Warrior
0/1
First strike, menace, trample
Partner (You can have two commanders if both have partner.)

Inspiring Statuary - (Gatherer) (Scryfall) (EDHREC)

{3}
Artifact
Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)