Update 6 knowledge articles to align with revised instructions

- performance/use-setloadfields-for-partial-records: Clarify that
  filter-only fields (SetRange/SetFilter) do not need to be listed in
  SetLoadFields — the DB resolves them via the index without hydrating
  the value into AL memory.

- performance/avoid-calcfields-in-loops: Add explicit exception for
  OnAfterGetRecord and OnValidate triggers, which are platform-managed
  and not developer-authored loops.

- performance/split-read-only-and-write-paths-to-avoid-locktable: Add
  ReadIsolation as the primary recommendation for read-only paths;
  LockTable reserved for confirmed write paths only.

- performance/prefer-direct-record-over-recordref: Scope the finding to
  hot unbounded loops (10k+ rows) over ledger-entry-scale tables;
  RecordRef in bounded/admin/setup contexts is not a concern.

- upgrade/enum-changes-must-be-additive-at-the-end: Replace direct
  ObsoleteState = Removed guidance with the two-stage workflow (Pending
  first, Removed later); reference use-obsolete-pending-before-removed.

- upgrade/use-datatransfer-for-large-dataset-initialization: Add the
  >300,000 records threshold as the concrete trigger for requiring
  DataTransfer.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

microsoft/knowledge/upgrade/use-datatransfer-for-large-dataset-initialization.md

@@ -15,7 +15,9 @@ An upgrade that populates a new field on millions of existing rows with a FindSe
 
 ## Best Practice
 
-Use DataTransfer for field-default initialization on existing tables, especially when the target is a ledger-entry or document-line table. Set tables, add source filters, add constant values, call CopyFields, clear, and repeat for additional slices. When trigger or subscriber behaviour is required, do that work separately against a filtered result set so the bulk update remains set-based.
+Use DataTransfer when initializing a new field on an existing table that **can contain more than 300,000 records**, or whenever a new field is added to an existing table and the initialization must run across all existing rows. Tables in the ledger-entry and document-line category reliably exceed this threshold; treat them as requiring DataTransfer by default.
+
+Set tables, add source filters, add constant values, call CopyFields, clear, and repeat for additional slices. When trigger or subscriber behaviour is required, do that work separately against a filtered result set so the bulk update remains set-based.
 
 See sample: `use-datatransfer-for-large-dataset-initialization.good.al`.