Englishal, that is a very good point. However, in my limited experience, the scenario you describe is quite unlikely. LARS frequencies generally tend to get very busy on good VMC days, and if you asked for a RAS on such a day you could expect it to be refused. But on a day when you have no choice but to fly in heavy IMC, I think it's very unlikely that you wouldn't get the service you required, because the frequencies are much quieter.
A bigger problem, IMHO, is those parts of the country where there is no LARS available. Much of Kent, I think, falls into this category, although the one time I've flown in IMC in that area Thames very kindly gave us a squawk and kept an eye on us.
FFF
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