Available on 1.7.10, 1.12.2, 1.14.4, 1.15.2, 1.16.5, 1.18.2, 1.19.2, 1.19.4, 1.20.1, 1.21.1, 26.1.x (Files (above) > View All > Game Version). Supported versions are in bold (but I'll try to support the other versions too within reason).

Place items down by pressing P while looking at a block. *
Rotate all with Sneak + P. Rotate item with Sneak + Use. (Requires empty hands)
* Note (for 1.16.4+): The P key used by Plonk conflicts with the Social Interactions Screen key so you'll have to change one or the other!

You are free to use this mod in any modpack (no need to ask!).

Item placed on sides of a block

Place up to 4 stacks of items on the side of any block using the Place Item key (defaults to P). (Max size of each stack is configurable and supports StackUp!)

Items can be individually rotated to 16 different directions (Sneak + Right Click using empty hands).

The whole tile of items can be rotated as a whole to 4 different directions (Sneak + Place Item key using empty hands).

Items can be extracted by automation but not inserted.

Can not be washed away by fluids anymore. ~~Placed items can be washed away by liquids.~~
Can be waterlogged (as of MC1.16.3+).

Config at config/plonk.cfg (before mc 1.13) or [save folder]/serverconfig/plonk-server.toml (after mc 1.13)

The look of the placed items and the mechanics are currently subject to change.

This video is very out of date

Known bugs:

Third person camera collides with block (1.7.10 and 1.12.2 only). Not sure how to tell minecraft to let the third person ray trace pass through (1.13+ has RayTraceContext.Visual) Translucent items (e.g. Stained Glass) cause other translucent things behind them not to render properly. (before mc 1.16)