Mr Smith.
You originally sited a scenario with WATLE as the descent point., now you've changed it, (sigh), to have a descent before WATLE.
To be in CTA prior to WATLE implies a descent from above 7500'.
The terrain in that region is around the 4000' level., therefore a fairly high rate of descent, or a long shallow descent, would be required before a CFIT. (assuming IMC are to the surface).
If you're in IMC prior to WATLE, then you'd better be IFR rated, which means that you have a reasonable idea of where you are, and what the LSALT is in your region., so sure, the controller may clear you to leave CTA early, but they, (nor any sane person) would expect you to do a descent to below LSALT unless specifically cleared to do so.
I love the inherent security of having another set of eyes (ATC) watching what I do, but I have a glimmering of just how difficult and complex things can be from the ATC's perspective.
To take a common computer analogy., how often have you clicked the OK button to a popup message without fully understanding what you've just 'OKed' ?.
It's actually a widespread human problem, (and a major reason for the existence of the 'Recyle Bin').
I'd prefer to not have ATCO's becomming desensitised by frequent alarms occurring every time that I exceed some lateral or vertical tolerance.