RTI and directors - can anyone spot a flaw in this plan?

I am a sole practitioner and within my client base there are 35 payrolls where only directors are on the payroll.  Currently I send out a monthly payslip, which has proved useful in the past as it means directors know exactly where they stand.  Nonetheless in the past 3 months 3 clients have informed me of some PAYE work they've had outside their limited companies.  In 2012-13, no problem - just re-jig the salaries.  But this would clearly not work in 2013-14 if submissions had already been made.

I want to keep my fees unchanged but feel going to just one payroll run in March 2014 is a bridge too far, also would cause problems for those clients who sail close to the wind on their loan accounts.  It seems that, as at present with "no PAYE due" submissions, we'll need to do something every quarter to keep the PAYE record alive.

So my plan is to run a payroll process - and send out a payslip - in week 11,24,37 and 50.  In other words, once a quarter halfway through the last month in the quarter.  As with everything I do, all clients will be informed about this in advance and offered the option to choose a different approach.

Please see if you can spot problems with this, all criticisms welcome.