Having to use signatures like 12/8 and increase tempo to make it match real tempo - that metronomes use and that full fledged notation software use.
 
For metronomes I think Korg BeatLab is excellent in it's simplicity.
Tempo is what it is - and you have volume faders for each time signature part
a) accent
b) quartnote
c) 8th note
d) 8th note triplets
e) 16th note
 
What you want in the click, just set fader of one or more of these to any level.
So ability to make such presets would be swell.
 
The most standard pattern on beat for shuffle would be 1st and 3rd triplet etc.
We should not have to fiddle around with workarounds for this.
And staff view simply do not support triplet rests.
 
So ability to select the proper grid while working with it - as the correct signature is chosen - how nice.
Tempos set in possible external sequencers, arpeggiators  will also work with the same tempo setting as daw has.
 
And using music.xml export will also be easier to use as is when transferred to other notation software.
 
I probably forgot many things won by this - so please fill in what is missing to motivate this makeover.
Or correct me if I missed something.
Thanks.