Would like ability to change rent due on a one to one or irregular basis for any given week/month without system changing all rent going forward

This would facilitate ease of entry for example when LHA sent a backdated change of rent allowance for the odd week or two.  I know we can edit the tenancy agreement directly but if there are a lot of backdated changes (and my local council seem particularly fond of doing this) it can become complicated would be a lot safer just to be able to this via a straight forward rent change option.