If i strapped LO in her carseat for naps? when i get her out of the car and she sleeps so much better when i leave her in her seat since she's strapped down. it's even better than swaddling. she can't get her arms up to her face to wake herself or break the swaddle. this seems cruel somehow if it isn't after taking her out of the car.
Re: would it be so bad...
I don't see why not!
I wish my LO would sleep in her car seat. It would make traveling much better!
There is data to suggest that the baby's rate of breathing decreases when in car seats...and that car seats should be used in cars only.
https://www.ctv.ca/CTVNews/TopStories/20061208/babies_carseats_061208/
I think if you are watching your LO and it is done in moderation than you should be fine.
we use the carseat for naps all the time. we also did this with dd1.
i confess that i don't strap her in, i just usually let her fall asleep on my shoulder and then gently ease her into the carseat.