Today I swapped out all of my keys that are used dual purpose for letters and layers to homerow layers. This prevents goofy things happening when rolling, and prefers-tap makes it so that keys that are rolled over get hit as letters instead of as layers. This was one of my biggest hurdles jumping into zmk, lt as a homerow key just does not behave the same as the ht/hm behaviors with tap-preferred set.
!!! seealso See previous commit where I added the hl https://github.com/WaylonWalker/zmk-config-42block/commit/9522c859cdf024a2c2b73931c130ddc907c09ffc
hl: homerow_layer { compatible = "zmk,behavior-hold-tap"; label = "HOMEROW_LAYER"; bindings = <&mo>, <&kp>; #binding-cells = <2>; tapping-term-ms = <150>; flavor = "tap-preferred"; };