2013 r1200rt master cylinder question

A friend and I were changing our brake fluid on our 2011 and 2013 r1200rt bikes. The bikes have 30,000 miles on them but this is the first time we've changed the fluid on these ourselves. My 2013 has always had more front brake lever travel than my friend's 2011. When we started to bleed the lines we discovered my 2013 kind of pushed the fluid up in the master cylinder reservoir like a burble (no air), the 2011 didn't (as expected). I have short videos.

Is the 2013 acting normally? Can someone with a 2013 confirm this fluid movement? I can see it happen at all times when looking thru the master cylinder reservoir bowl as I squeeze the brake.

The 2013 braking ability is fine. The level travels closer to the hand grip but it doesn't bottom out and is a bit spongier than the 2011. We bled it twice, no air bubbles. We used the Hex GS-911 to test the ABS on both bikes and they are fine. Another difference, the 2011 master cylinder seems to be mounted on a rubbery base, it moves, where as the 2013 master cylinder mount is rigid. I don't know why or what's changed.

I did my first brake fluid replacement on my '13 (I just bought the bike and was doing the 6k service). I also noted that the fluid tended to back-flow into the reservoir. If was too sporty about it I'd get a mini-geyser. I thought the lever felt a little spongy before, got really good after, and now is back to a little spongy. The brakes work fine so I don't think there's anything wrong but, of course, what do I know? I just got the thing. I'd be interested in learning from the Collective.

FWIW, you'll note the earlier bike has a bleed valve at the master cylinder and the 2013 doesn't.

I don't know what this means, as I've not even looked up the bleed procedure for mine.