I think that a lot of (pergaps even most) parents occasionally take chances and do things they know they aren’t supposed to do. For me, it was using the buckles on the bouncy seat when Breanna was a baby. Once she started wriggling around, I buckled her in so that she wouldn’t slide off and onto the floor, but when she was just a twitchy blob of a baby who couldn’t move much, I only strapped her in about half the time. If I was going to be across the room or if I had to run to another room for a second (or if I was showering or she was sleeping of course) I did. If I was peeing or standing right beside her, I didn’t. I know the safety sticker says to always use the buckles, but there you have it: I didn’t always listen.
For about three weeks now, I always strap her in, no matter how close I am. Even though the seat is directly at my feet and within arm’s reach when I sit down to pee, I still make sure she is firmly and safely buckled in. Why? Because three weeks ago she decided that sitting back in the bouncy seat is for pussies and that although she hasn’t even mastered rolling yet, she’s going to practice sitting up.

And so buckles it is, lest she topple over onto the floor.
I have the same chair and I wish it had a shoulder strap or something. My daughter sits straight up in that thing and it makes me feel like she’s going to topple out. I had the same problem with my first daughter. My little one is almost 6 months old now and she sits up like that to fall asleep in her stroller too. Too cute!