Agree "Progress" comment and +1.
I'd suggest it is just as common for PCs to "misunderstand" the requirements of s85 as it is for them to "misunderstand" so many other issues - dispensations for an easy example.
Shortly after becoming the chair of the PC I highlighted the inappropriate process which had previously existed for apologies for absence and the failure to properly hold and record a vote to accept / reject said apologies.
It was simply a case of previous chair(s), clerk(s) and Cllrs being ignorant of the proper procedure.
I asked that there be a simple record of those in attendance noted on the minutes. That was the record of attendance. Those that were not in attendance were noted as such. Apologies are subjective and really, just a matter of courtesy - they have no effect upon whether a person is actually present or not.
If you're there, you're there. If you're not, you're not. Simple as that.
If after 6 months you haven't been there you are disqualified by dint of statute. That's pretty simple too.
Attendance must be recorded on minutes - if there are 6 months worth of minutes that show non attendance then its game over. Simple as that for a small - med, even a large PC.
A town, district or unitary authority may have the resources to integrate attendance records with individual Cllr profiles and encompass things like voting record but at the minnow level - just record attendance on the minutes and have a calendar to hand.