Is your feature request related to a problem? Please describe.
Not quite, I suppose, but when decorating I always get quite frustrated how limited vanilla flower pots and the various planters introduced by mods are. On the other hand, mods like handcrafted add decorative pots/vases/urns but with no way to put flowers in them.

It's probably not the most useful nor the most requested function for most people but personally, I use flowers for my builds a lot and am always annoyed to have to use the boring minecraft pot when I'd maybe like a stone pot with a large fern sitting on a column in my mansion.

Describe the solution you'd like
A functional copycat-like vase that allows you to texture it using a material (obviously) and add any kind of small or large flower/fern into it.
Additionally, the way copycat slices can be made larger or bigger by right clicking them with themselves, it would be cool if one could cycle between several vase/pot sizes/designs.
I was thinking something along the lines of Handcrafted's pots, where you have 4 different sizes/shapes for each pot design (see screenshot).

Describe alternatives you've considered
Vanilla decorated pots can be used by hiding a flower pot in the upper part of the block, but are limited as they can't be dyed.
Many mods introduce planters, but those are usually limited to one design or material.
Some mods introduce decorative vases and pots but these can't hold flowers.
A rather time consuming workaround is to use said vases and manually spawn a flower as block display on top of the vase using vanilla commands.

Additional context
Screenshot from Duniverce's review of handcrafted on youtube, showing several simple sizes/shapes for a given vase design.