I have updated the wiki entry on Reading Plans with a method for creating manually customised reading plans in Logos 4 that accurately follows M'Cheyne or Horner rather than an automatically generated approximation.
This method is neither recommended nor support by Logos, may have unintended consequences, and is used at your own risk.
The instructions are on the wiki: http://wiki.logos.com/Reading_Plans
The required reading plan xml for M'Cheyne 2010 and Horner 2010-11 (courtesy of Robert Warren) is available here:
M'Cheyne: 8270.McC.xml
Horner: 6567.Horner_2010-11.xml