diff --git a/core/autoload/ui.el b/core/autoload/ui.el
index 80735e26f..af5ef34f1 100644
--- a/core/autoload/ui.el
+++ b/core/autoload/ui.el
@@ -1,7 +1,7 @@
 ;;; core/autoload/ui.el -*- lexical-binding: t; -*-
 
 ;;
-;; Public library
+;;; Public library
 
 ;;;###autoload
 (defun doom-resize-window (window new-size &optional horizontal force-p)
@@ -24,7 +24,7 @@ are open."
 
 
 ;;
-;; Advice
+;;; Advice
 
 ;;;###autoload
 (defun doom-recenter-a (&rest _)
@@ -43,7 +43,7 @@ In tty Emacs, messages suppressed completely."
 
 
 ;;
-;; Hooks
+;;; Hooks
 
 ;;;###autoload
 (defun doom-apply-ansi-color-to-compilation-buffer-h ()
@@ -57,9 +57,17 @@ In tty Emacs, messages suppressed completely."
   "Turn off `show-paren-mode' buffer-locally."
   (setq-local show-paren-mode nil))
 
+;;;###autoload
+(defun doom-enable-line-numbers-h ()
+  (display-line-numbers-mode +1))
+
+;;;###autoload
+(defun doom-disable-line-numbers-h ()
+  (display-line-numbers-mode -1))
+
 
 ;;
-;; Commands
+;;; Commands
 
 ;;;###autoload
 (defun doom/toggle-line-numbers ()
diff --git a/core/core-ui.el b/core/core-ui.el
index ea9bcdbf5..7ea90354c 100644
--- a/core/core-ui.el
+++ b/core/core-ui.el
@@ -514,16 +514,16 @@ windows, switch to `doom-fallback-buffer'. Otherwise, delegate to original
 ;; Explicitly define a width to reduce computation
 (setq-default display-line-numbers-width 3)
 
-;; Show absolute line numbers for narrowed regions
+;; Show absolute line numbers for narrowed regions makes it easier to tell the
+;; buffer is narrowed, and where you are, exactly.
 (setq-default display-line-numbers-widen t)
 
-;; Enable line numbers in most text-editing modes
+;; Enable line numbers in most text-editing modes. We avoid
+;; `global-display-line-numbers-mode' because there are many special and
+;; temporary modes where we don't need/want them.
 (add-hook! '(prog-mode-hook text-mode-hook conf-mode-hook)
            #'display-line-numbers-mode)
 
-(defun doom-enable-line-numbers-h ()  (display-line-numbers-mode +1))
-(defun doom-disable-line-numbers-h () (display-line-numbers-mode -1))
-
 
 ;;
 ;;; Theme & font
@@ -539,6 +539,8 @@ behavior). Do not set this directly, this is let-bound in `doom-init-theme-h'.")
   "Loads `doom-font'."
   (cond (doom-font
          (cl-pushnew
+          ;; Avoiding `set-frame-font' because it does a lot of extra, expensive
+          ;; work we can avoid by setting the font frame parameter instead.
           (cons 'font
                 (cond ((stringp doom-font) doom-font)
                       ((fontp doom-font) (font-xlfd-name doom-font))
@@ -547,6 +549,8 @@ behavior). Do not set this directly, this is let-bound in `doom-init-theme-h'.")
           default-frame-alist
           :key #'car :test #'eq))
         ((display-graphic-p)
+         ;; We try our best to record your system font, so `doom-big-font-mode'
+         ;; can still use it to compute a larger font size with.
          (setq font-use-system-font t
                doom-font (face-attribute 'default :font)))))
 
@@ -639,7 +643,8 @@ startup (or theme switch) time, so long as `doom--prefer-theme-elc' is non-nil."
 (put 'customize 'disabled "Doom doesn't support `customize', configure Emacs from $DOOMDIR/config.el instead")
 (put 'customize-themes 'disabled "Set `doom-theme' or use `load-theme' in $DOOMDIR/config.el instead")
 
-;; doesn't exist in terminal Emacs; we define it to prevent errors
+;; Doesn't exist in terminal Emacs, so we define it to prevent void-function
+;; errors emitted from packages use it without checking for it first.
 (unless (fboundp 'define-fringe-bitmap)
   (fset 'define-fringe-bitmap #'ignore))