When I asked around, colleagues just tell me- "it doesn't affect us" or as you said "we are light today". Someone also suggested 2X the 3 degree glide path- eg at 1nm below 600' is ok.
Sometimes there is an INTAM which which tells use to input a specific obstacle into the performance software, hence the belief that they check the obstacles. No assurance of sort given by them (flt ops people or performance software provider) though.
Thanks for the input guys.