I played around with the script file again. I was going to tidy up all the endings so that you get Emma turning up to Matthew's late after Martin's visit, and stuff like that, but for a non-coder like myself, it was too much of a minefield!
Anyway, the attached script file fixes the "Epilogue" bug, and also adds in another check to change the "option46" flag back to false in Ep7, so those playing the cheating path from saves at the start of Ep7 will now be able to see Emma's perspective on her anniversary.
I think your options on the cheating path now are:
If cheating with Martin but not Matthew - scene will show Emma's perspective as Martin comes over for sex, but will miss Matthew's house because Emma was late.
If cheating with Martin and Matthew - scene will show Emma's perspective as she goes to Matthew's and has sex with him, nearly getting caught.
If cheating with Matthew but not Martin - I don't have a save to test this one, is it actually possible? I presume so, as there is content in the epilogue for it... Anyway, it should show Emma's perspective as she goes to Matthew's and has sex with him, nearly getting caught (then the epilogue will feature her actually getting caught with Matthew, on another occasion).
Drop the script.rpy file into your "game" folder and load the game and your save. I recommend making a backup of the existing script file just in case. I've tested this on my saves, but it's always recommended to be careful!