Absolutely correct, you can renew by cross credit. Standards Document 14 was last updated in 2014, the regulation changed in 2019 to allow renewal by cross credit hence no reference.
Make sure you're looking at the latest version of the Part FCL Easy Access Rules (August 2020) - Appendix 8:
Credits shall be granted only if holders are revalidating or renewing IR privileges for single-pilot single- engine and single-pilot multi-engine aeroplanes, as appropriate.
Replied to your PM also!