diff --git a/lib/svgo/plugins.js b/lib/svgo/plugins.js
index 5719d1633..efeb01b14 100644
--- a/lib/svgo/plugins.js
+++ b/lib/svgo/plugins.js
@@ -14,7 +14,7 @@ const { visit } = require('../xast.js');
  */
 const invokePlugins = (ast, info, plugins, overrides, globalOverrides) => {
   for (const plugin of plugins) {
-    const override = overrides == null ? null : overrides[plugin.name];
+    const override = overrides?.[plugin.name];
     if (override === false) {
       continue;
     }
diff --git a/plugins/plugins-types.ts b/plugins/plugins-types.ts
index daf5ff0ad..a3f8852f0 100644
--- a/plugins/plugins-types.ts
+++ b/plugins/plugins-types.ts
@@ -73,10 +73,28 @@ type DefaultPlugins = {
   };
   mergeStyles: void;
   inlineStyles: {
+    /**
+     * Inlines selectors that match once only.
+     *
+     * @default true
+     */
     onlyMatchedOnce?: boolean;
+    /**
+     * Clean up matched selectors. Unused selects are left as-is.
+     *
+     * @default true
+     */
     removeMatchedSelectors?: boolean;
-    useMqs?: Array<string>;
-    usePseudos?: Array<string>;
+    /**
+     * Media queries to use. An empty string indicates all selectors outside of
+     * media queries.
+     */
+    useMqs?: string[];
+    /**
+     * Pseudo-classes and elements to use. An empty string indicates all
+     * all non-pseudo-classes and elements.
+     */
+    usePseudos?: string[];
   };
   mergePaths: {
     force?: boolean;
@@ -89,13 +107,13 @@ type DefaultPlugins = {
      * Disable or enable a structure optimisations.
      * @default true
      */
-    restructure?: boolean | undefined;
+    restructure?: boolean;
     /**
      * Enables merging of @media rules with the same media query by splitted by other rules.
      * The optimisation is unsafe in general, but should work fine in most cases. Use it on your own risk.
      * @default false
      */
-    forceMediaMerge?: boolean | undefined;
+    forceMediaMerge?: boolean;
     /**
      * Specify what comments to leave:
      * - 'exclamation' or true – leave all exclamation comments
@@ -103,7 +121,7 @@ type DefaultPlugins = {
      * - false – remove all comments
      * @default true
      */
-    comments?: string | boolean | undefined;
+    comments?: string | boolean;
     /**
      * Advanced optimizations
      */
diff --git a/plugins/removeUnknownsAndDefaults.js b/plugins/removeUnknownsAndDefaults.js
index c67845cd5..410b36554 100644
--- a/plugins/removeUnknownsAndDefaults.js
+++ b/plugins/removeUnknownsAndDefaults.js
@@ -182,16 +182,12 @@ exports.fn = (root, params) => {
             attributesDefaults.get(name) === value
           ) {
             // keep defaults if parent has own or inherited style
-            if (
-              computedParentStyle == null ||
-              computedParentStyle[name] == null
-            ) {
+            if (computedParentStyle?.[name] == null) {
               delete node.attributes[name];
             }
           }
           if (uselessOverrides && node.attributes.id == null) {
-            const style =
-              computedParentStyle == null ? null : computedParentStyle[name];
+            const style = computedParentStyle?.[name];
             if (
               presentationNonInheritableGroupAttrs.includes(name) === false &&
               style != null &&