When using a custom optionLabelTemplate and valueTemplate with Font Awesome dual tone icons it seems we need to set the display css class to inline-flex to keep the icon from separating (Kendo UI v2020.3.1021 in Chrome v88.0.4324.104).
$(
"#dropDownList"
).kendoDropDownList({
optionLabel:
"Select One"
, template:
"<i class=\"#=icon# mr-1\" style=\"font-size: 25px\"></i>#=name#"
, optionLabelTemplate:
"<i class=\"fad fa-hard-hat mr-1\" style=\"display: inline-flex\"></i>Select One"
, valueTemplate:
"<i class=\"#=icon# mr-1\" style=\"display: inline-flex\"></i>#=name#"
...
});