For the specialty switch you linked, You aren’t going to get three of their switches in a box because they have the switch integrated with the cover plate. Do you need a switch you can wash down with a water and a squeegee or do you just want to control three circuits with zwave switches in one box?

You can get three switches like this

GE Enbrighten Z-Wave Plus Smart Light Switch 2-pack with Quick Fit & SimpleWire, 3-Way Ready, Works with Alexa, Google Assistant, ZWave Hub Required, Repeater/Range Extender, White/Light Almond, 47900 https://www.amazon.com/dp/B07X84WRGR/ref=cm_sw_r_cp_api_glt_fabc_6PJSP710QVRXVP83M78K?_encoding=UTF8&psc=1

(Just picked the first hit. There are many brands and styles available)

And put a three gang cover plate like this on it.

ENERLITES Decorator Light Switch or Receptacle Outlet Wall Plate, Size 3-Gang 4.50" x 6.38", Polycarbonate Thermoplastic, 8833-W, White https://www.amazon.com/dp/B01I0FQIS4/ref=cm_sw_r_cp_api_glt_fabc_7EA22W9CNZGKZHEAVSVF

You just connect the three lines to the hot source, tie all the neutrals together, and the loads go to each switches device.