sizing all your projects so they neatly fit in 2-week chunks also never works for every dev team I've met. There's always either some slack where the thing took 8 days not 10, or some part of the deliverable gets hacked off into another chunk so it fits.

and, ofc, estimating the time to deliver is impossible, so you end up scheduling a sprint demo that might or might not happen depending on how well the project is going.

Or, as I found, people are perfectly OK with scheduling demos in at short notice and being flexible about their expectations.