The iRp player is controlled by each style's algorithm. There's no iRp notation convention to force a chord to be sustained.
If you were to select the Jazz Long Notes style for your example, every chord would hold for the whole measure.

- - * Tuning * - Exercise

If my goal was to provide performance instructions for the musician(s) I’d likely use a fermata (no effect on player) because it’s convenient. Yes, it often means “extend” the note, but I suppose I’ve also used it to mean “present” the note.

Placing ring, hold or sustain using text could also work for the musicians (no effect on iRp player.)

)BOB