Damage preview shows damage with modifier even when it would not apply due to involving no dice rolls

[krbz999]

Create item that deals 1 damage.
Preview formula on actor sheet shows 1+ mod, but the eventual roll is just 1 as it should be.

[Fyorl]

There's an explicit rule for this in the 2024 PHB but I can't find an equivalent in the 2014 PHB. Do you know where it is? Or does the behaviour here need to depend on the rule setting? The preview should of course match what is rolled regardless.

[krbz999]

Best I could find was a JC tweet.
https://x.com/JeremyECrawford/status/780902953536266241

Putting this behind the rule setting would probably be ideal then. I guess the alternative would be to use the ruleset set on each monster, but that wouldn't cover player characters.