url: more comments to explain lazy searchParams updating

lib/internal/url.js

@@ -776,10 +776,11 @@ class URL {
 
   static {
     setURLSearchParamsModified = (obj) => {
-      // If URLSearchParams gets updated, use that as the source-of-truth for search.
+      // When URLSearchParams changes, we lazily update URL on the next read/write for performance.
       obj.#searchParamsModified = true;
 
-      // If URL has an existing search, remove it without cascading back to URLSearchParams
+      // If URL has an existing search, remove it without cascading back to URLSearchParams.
+      // Do this to avoid any internal confusion about whether URLSearchParams or URL is up-to-date.
       if (obj.#context.hasSearch) {
         obj.#updateContext(bindingUrl.update(obj.#context.href, updateActions.kSearch, ''), false);
       }
@@ -845,7 +846,8 @@ class URL {
   }
 
   #checkSearchParams() {
-    // If URLSearchParams has been modified, reflect that back into URL.
+    // If URLSearchParams has been modified, reflect that back into URL, and do not cascade back.
+    // This is done lazily to greatly improve performance when URLSearchParams is updated repeatedly.
     if (this.#searchParamsModified) {
       const href = bindingUrl.update(this.#context.href, updateActions.kSearch, this.#getSearchFromParams());
       this.#updateContext(href, false);