Extend zone buff instead of replacing it? or at least warning message?

[TheVictorious]

Hi,

A friend applied guide buff wrongly for me that I was already activated, so the old buff still had a few hours left but it simply replaced with new one with new counter (6 hours), he did not get any warning that the zone buff is still active, and my zone buff not extended (like prem "zone buff"), it must be at least one of these options; a warning message or extend current one, so not to waste the buff.

[Dorotheus]

Personally I prefer to have them extended like prem.

[Xibor]

I agree that either a warning or an extension is warranted.

[topgearfan]

Personally I prefer to have them extended like prem.

[Thejollyone]

Id prefer it extended too, but would this not then constitute a "stacked" buff?