OMG, that is taking the piss!
And every time they spot something new to complain about. For example, they found 70+ flourescent bulbs down the side of the garage - we didn't know they were there as it's a tiny space you can't really easily see down but they were looking as they're planning a big extension. This is fair enough and not outrageous of them to be concerned with (and our fault for being naive when we bought the home to not check this), but it then meant we had to take multiple trips to the tip to get rid of it all. More fool us because the people we bought from left loads of building type crap (like the bulbs) around the garden and we didn't realise we could do anything about it! (lesson we are learning now that it's all being picked apart and we're having to dispose of it all for our buyers).
This time, we gave them the option to buy our NEST off of us (£80 I think it what I put and it's only a few years old) OR we'd have a new one put in a new one. They've said to their solicitor that they are aware we're removing the thermostat (so clearly they aren't willing to buy it) so that's fine, but they want to know exactly what model thermostat will be replacing the NEST and want all the certifications from a licensed person for the installation of the thermostat. It's just ball-achey stuff like that every time they come around. Part of us is like "just leave the NEST to make our lives easier as we don't need this extra stress in our lives at the moment" and the other (pettier) part is like "no no, we'll get it all signed off and give them the shittest thermostat we can find).
I guarantee the longer this goes on where we don't exchange, the more they are going to want their builders around to start drawing up plans and the more they will spot new things we need to sort out (or money they'll want knocked off) and I just don't need the extra stress in my life. I was being nice before, but now I'm just annoyed and done with it so I'm putting my foot down to say no more until exchange (at a bare minimum....as I'd prefer no more until you physically own the place). Fingers crossed we get an update in the next few weeks with a clear exchange and move date as this is getting tiring.