Is there added value in having your own presentation layout and using it consistently?
I don't think there's any inherent value in having your own "signature" presentation layout.

Generally, you want to keep the focus on the content of your talk.  If people are noticing your layout, they are paying less attention to your science.  Would you rather stick in their minds as "the speaker with the cool result" or "the speaker with all those weird colors on their slides"?

If you really dislike the usual templates, or you can make your own workflow more efficient by creating your own, then go ahead and do it.  But I would suggest keeping your (visible) changes conservative; if your layout is radically different from what people are used to seeing, it may become distracting.