Port MRs 1450 and 1459 into main-pc

• Link to issues in BASOP repo:
  • #1622 (closed)
  • #1623 (closed)
• Link to original MRs in float repo:
  • ivas-codec-pc/ivas-codec!1450 (merged)
  • ivas-codec-pc/ivas-codec!1459 (merged)
• Requested reviewers: