Ski binding adjustment question

So I made an interesting discovery recently - I think the bindings (Marker Griffon 13) I have been skiing for ~2 years don't actually fit my boots 100% properly. So I bought my skis and bindings and had a shop mount the bindings and fit them to my boots. However, shortly after I bought new boots that are a smaller size than my previous boots. I adjusted the bindings myself to fit them to the new boots and everything seemed fine and I've skied them a considerable amount with no issues.

Recently I was starting to do some adjustments to the bindings and was surprised when the heel piece just completely slid forward and detached from the binding track. I thought something had broke so I checked the other ski and it did the exact same thing. So I did a bit of internet research and I think what happened is that when I turned that screw in the back of the binding to adjust the forward pressure to fit the new boot, I pushed it so far forward that it was no longer in the (metal track thing with the grooves that holds it in place). So I think my new boots are just slightly too short to fit my old bindings properly (the difference is very small - about a few mm).

Is there any easy way to fix this by doing some sort of adjustment or do I need to have the bindings remounted? I think the toe piece is in a fixed position and can't be adjusted in the same way as the heel but if there's any possibility to move that a bit that could do the trick.

Or am I probably ok to just keep the bindings like this because it seems to have worked out for me for quite a while now? My impression is that the forward pressure is like 95% of what it should be and the heel piece will stay in place when the boot is in there. It can only slide forward and therefore, I don't think there's a risk of it popping off while I am using them. Also note that these are kind of my backup skis that I ski with family and I have another pair that I use for more intense skiing. I still do ride these hard enough though...

EDIT - I played around with the binding some more and I think I now have a better understand of what's going on. I think the heel track is mounted too far back by the ever so slightest amount but it doesn't impact the integrity of the way the binding needs to work. The screw grooves/rungs (for lack of a better word) are essentially engaged with the track by being pressed up against the last rung of the track (it works as a backstop) but it is not threaded into the track past the first rung, which is why it can move forward. Note that at this position the forward pressure appears to be correct based on the position of the related screw being flush with the rest of the binding. If I back the screw off slightly the binding will thread into that rung and hold it in there so it can't move forward. But at that position the forward pressure is slightly too low.

Not 100% ideal but I am pretty sure the binding is still working as designed and perhaps not worth the risk/hassle/cost of redrilling new holes less than a cm from the original ones. If anyone has any thoughts on this please let me know. If there's some sort of catastrophic failure possible that you are aware of I'd appreciate if you could describe it to me. Obviously if there's a real risk, paying a shop to remount is a no brainer.

And as a side note - I had adjusted my other pair of skis in the same way and they were fine. I think the difference is extremely small and I just got a little unlucky that the original mount was a few mm back from where it would ideally be for my new boots.