courier collections- do any have a narrow collection window?

[cluttered]

OK, following on from my thread below I have decided to use a courier service to send an item worth £100 rather than trusting Royal Mail standard parcel which is unsigned for, especially since I see the buyer has only 4 feedbacks over as many years. I have looked at parcel2go and the quotes seem quite reasonable but I can't find any information on what hours they collect between. Even if I can work from home one day I will need to pop out to drop the kids at school and collect them so I am wondering whether some allow you to specify morning or afternoon only collection?

Also, I have emailed the buyer to ask if someone will be in to receive the parcel but if they don't respond I guess I will have to send anyway, so what happens if no one is home, do any couriers automatically try to redeliver? What happens if the buyer fails to rearrange redelivery and the item gets left with the courier and then the buyer claims their money back from Paypal?

Does anyone have any advice please