GPS-RTK Dead Reckoning Breakout Accuracy with intermittent RTK

Hi,

I need to understand the logic in the functioning of this unit.

The video says it can maintain accurate tracking without GNSS signal, which I understand is subject to general GPS accuracy.

BUT, in my application GNSS is not a problem and will very rarely be a problem BUT I need RTK accuracy, the RTK signal will be intermittent as I am using GSM to obtain the RTK feed.

So my question is, if I lose the RTK feed for a minute or two, how accurate will the dead reckoning positions be and will it immediately drift to normal GPS accuracy?

Do I need to install the wheel ticks sensor to maintain short period accuracy?

Thank you…