Can we have a mode for the building gadgets that behave similarly to Chisel and Bits's 'Same Material' placing style? In a sense, kinda like Builder's Wand, but instead of being forced to place the exact same material(e.g. cobble on cobble) as the target, the building gadget places the block that you have shift-right-clicked before instead(e.g. wood on cobble).
I鈥檇 rather not add that feature. You can just shift click the block you鈥檙e building off can鈥檛 you?
I don't think I did a good job explaining, so here's pictures to help me elaborate.

Left is the starting base. Center is built with Better Builders Wand. The limitation of builder's wand is that player has to use blocks of the same type. In this case, the extended part has to be yellow wool for the yellow part, and cyan wool for the cyan part. The building mode: same material I suggested will let players extend yellow/cyan part with any blocks they want, just by shift-right clicking a different block with the building gadget (shown on the right).

I think this will be especially useful when dealing with complicated designs. I build the example above with builder's wand and exchanging gadget. It took many rounds of going around and exchanging blocks because of its uneven shape. Having a 'same material' mode will help streamline the process greatly.
Right now the exchanger only replaces as per C&B's 'same material' mode, and the builder doesn't place as per it. It would be nice if both gadgets had both modes: 'replace same blocks in area' and 'replace all blocks in area' for the exchanger; and 'place on same blocks' for the builder.
EDIT: I forgot about fuzzy mode in the exchanger, which already replaces all blocks in the area.
The builder's 'place on same blocks' could check all blocks in the plane of the face clicked, and only add blocks if the position offset in the opposite direction to the face clicked contains the same block as the one clicked.
Hrm I see what you're asking for. I'll consider this addition, not 100% sure either way if I want to add it just yet :).
@Direwolf20-MC
If I would make a PR, do you prefer a separate gadget or a mode of the existing building gadget?
A mode of the existing building gadget would be lovely. It will help reduce the clutter on hotbar.
I'm having a go at implementing this.
@Phylogeny Sorry didn't see that
Released in v2.6.2
Most helpful comment
Hrm I see what you're asking for. I'll consider this addition, not 100% sure either way if I want to add it just yet :).