I bet, that sounds fun Did you get married during the pandemic?
My "stack" is attached - you can see the DeBeers eternity band (which I'm pretty was called the Match Band when I got it https://www.vogue.co.uk/article/de-beers-match-bands, might be similar to this current offering https://www.debeers.com/en-us/aura-eternity-band-in-white-gold/R102200.html) is slightly "taller" than the T Metro bands. DeBeers sizes differently so my wedding band is a 56 whereas my Metros are are 7.5 - similar but not identical.
Toying with adding a totally different style to the grouping... but no idea how that'd look! Maybe the Jazz (https://www.tiffany.com/jewelry/rings/tiffany-jazz-band-ring-GRP10140/) or the Petal (https://www.debeers.com/en-us/petal-band-in-rose-gold/R102311.html)
Your current set is so pretty! Of the two options you noted, I especially like the DeBeers Petal band. I think a Metro on either side of that or the Jazz band would look lovely.
I received my Legacy/Metro set as an anniversary gift. My original wedding band is a yellow gold Etoile, and later I got a platinum Etoile. Platinum is more durable, and fun I thought to have a white metal option, too. The Metro bands look nice worn on either side of an Etoile, as well. Pic of my Etoiles and Legacy/Metro set below, for size reference.
So many fun options to choose from, let us know what you decide!