I’ve configured dozens of networks over the past decade to use the same SSID for both bands, and have never observed a real world issue with myriad clients. The only tweak is sometimes the 2.4GHz Tx power needs to be dropped, but it’s rare.
Some locations I’ve had to create additional bespoke SSIDs for a specific band, but it’s only because the customer has explicitly requested it because they think it matters.
Weirdest bespoke network I have is one that only exists for an LG washing machine. It’s network stack eventually gets corrupted when network isolation isn’t enabled and receives some sort of broadcast packets.
Some locations I’ve had to create additional bespoke SSIDs for a specific band, but it’s only because the customer has explicitly requested it because they think it matters.