The - Elite,
I certainly see the problems that Heli eng is talking about . I would imagine there would/could be a little flexibility from the CAA if you did not get the time frame of Exams passed/work experience gained absolutely down to the second. I think that if there are any grey areas with a persons particular circumstances , a carefully worded letter addressed to an 'Organ grinder' at aviation house would be of benefit to you.
If i was in that situation , I think the best bet would be to get all of the the examination modules taken and passed say within 4.5 years and then apply for the licence with 6 months of 'Work experience' still to go. in fact it might even pay you to get the modules out of the way soonest then start sending them letters asking for your licence every 6 months. The CAA have changed the rules in the recent past (ie only 1 month wait for a resit instead of usual 3 ) so there is no reason to think they won't change them in the future. if your letter is accompanied with one from your senior maint manager or quality manager as well , explaining whata great worker you are and how short of engineers they are ... well who knows - you don't ask ,you don't get.
HTH.