Steel Defender of Battle Smith and how to interpret spell attack modifier as to hit bonus

My battle smith artificer has an attuned all purpose tool which boosts his spell attack modifier. On DnD Beyond, the to hit bonus of my steel defender is the initial modifier, not the boosted amount. To be specific, the default modifer is +7, but rare all-purpose tool boosts it to +9 after attunement. For steel defender in the actions tab, it is still +7.

For fellow players and DMs, should I use the boosted spell attack modifier or default modifier? 

Thanks! I will mention this to my DM at my next game and will manually add the bonus to that specific action. 

Sounds similar to dndbeyond not calculating True Strike bonuses properly.

Steel defender for battle smith artificer is under the 'Features' section of the sheet. The updated version includes force empowered rend as an action. The legacy 2014 from Tasha's requires players to remember to roll using spell modifier from sheet.