Made a fighter with an Aberrant Dragonmark to cast the Green Flame Blade cantrip with flame tongue weapon. Gave him Illusionist’s Bracers so he can attack with it twice instead of only once.

But I also want to include a Spellguard Shield. Is it ok to wear bracers and a shield at the same time?

Extra: With my current stats my regular flame tongue with extra attacks does 96 damage at max. Using the GFB combo achieves that even with only two attacks, but also adds the secondary target damage of 56 max total.

Unless the item says otherwise, like the Bracers of Defense, then yes, it's ok.

Bracers of Defense have a specific note: "if you are wearing no armor and using no shield"

But both Bracers of Archery and the Illusionist's Bracers you're asking about, have no such note.

With the absence of anything specific. RAW suggest there's no reason you cannot wear the Illusionist's Bracers and a shield

Answer: YES

And this applies for magic shields as well like the Spellguard Shield, correct?

Unless the magic shield has a specific rule that it can't be used with the bracers then there's no generic, written rule to say that shield and bracers (magic or mundane) cannot mix and add any benefits together.

The Bracers of Defense are the exception to the rule because they have a specific addition that notes they won't work with shields.

Thank you :3