If you have the flexibility, don't sign until after your walk-through and after any issues are fixed that arise from that (and there will be a few to many).
Take your time with the PDI, make sure everything is explained and works. Take pictures and/or videos during the inspection which may help you understand how something works later down the road. If you are unsure about anything stop and ask.
And remember
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Bill & Pam
2014 Trilogy 3650RE
2015 F350 PSD