I don't do weddings but I do print quite a bit, mostly sending images you to a lab, as I only have a basic A4 Pixma multifunction at home. I use a workflow system fully based on LR, and usually for printing I go through the Print module for both the local and remote printing devices. When I export from LR for printing I always use the colour space that is recommended by the lab. For most of my prints that will be using the .icc profile supplied by the lab for the specific papers in use. For any system for which they don't supply a profile then I use the colour space they advise, which is always sRGB. The normal service I use at the lab allows me to specify No conversion/No adjustment, and everything else that they do will convert to sRGB before it goes to the printing device. Of course for my locally attached printer, a Canon Pixma MG5150, in which I normally only use OEM inks and Canon Platinum Pro paper, LR uses the appropriate Canon supplied .icc profile for the paper, although of course there is not actual file created in this process. Way more than 98% (but less than 99%) of my images processed in LR only exist as CR2, or DNG, files until they are exported for a specific purpose, printing or uploading to a website for example. For the 1% to 2% of images that do have to be converted to RGB for additional editing in PS they are saved as 16 bit ProPhotoRGB PSD files and then managed from LR in the same manner as the RAW files.
Over the years I have seen multiple posts my a member whose name escapes me trying to find a lab that would use any working profile other than sRGB, without first converting to sRGB, and was only ever able to find one confirmed case of a lab printing in aRGB. This excludes those labs that allow you to use their hardware specific profiles with zero conversion. Given how hard it is to find a lab that uses anything other than sRGB I personally would not give anyone files in anything other than the sRGB. I only do a small amount of commercial work for a couple of small businesses, and that is product and other related work and I would not supply my clients with anything other than sRGB JPEG files, because they simply would not know what to do with anything else. I have even dealt with some small print shops for offset press work, and often when speaking to them I will ask for submission requirements and what colour space was required to be met with
??. In that circumstance I'm sending sRGB, because that's what they will be getting from most people, so statistically they are less likely to stuff it up. If that is the situation for commercial situations, with people who should know this stuff, I would not consider giving a bride or other family member a file in anything other than sRGB because it is a 99% probability that they would not even know that an image file had a thing called a colour space, let alone what to do with it. I absolutely would not be giving anyone a file that was in ProPhotoRGB, since that colour space should only be used in 16 bit images, and I'm not giving anyone my master PSD files to play with. Even giving someone a 16 bit TIFF in ProPhotoRGB with the layers flattened is not really a goer, most folks would again have no clue as to what to do with it.
Being ex forces I strongly believe in KISS, and KISS is a sRGB JPEG file, because if you give them anything else they will find a way to bugger it up, and cause you problems sorting it out. In just the same way that you ensure that you give them files with the PPI value set to 300 PPI, because otherwise they will go to some lab to be told that a 6000×4000 pixel image is too low resolution to print, because the lab's ROEs software only looks at the PPI tag. After all the PPI tag really only matters if you are opening the image file in some DTP programs like InDesign, which by default looks at the PPI tag, and actually uses it to set the default image dimensions in the publication. Really annoying when you open a full size image from a P&S camera that a contributor sent you, to find it has set the PPI at 72 by default, and suddenly the image box becomes something like four feet by three feet, and you have to zoom right out to resize it. Oh and even then I have never found the need for anything other than sRGB, although the publication I was editing/publishing was not offset printed, we used a laser printer and folded/stapled by hand, since distribution was normally only about 150 copies on a roughly weekly basis.
So in summary my output files will always be in sRGB unless there is a very specific requirement otherwise.
Alan