The lay rule will trigger as soon as the LTP is greater than the stored value (the back bet rule when the LTP is less than the stored value)
if you want to put a limit on one or both you'd need to add another condition
The simplest would be a fixed odds condition if you just wanted to enter a fixed price for every race
If you wanted to do it relative to the SP each race then you'd need to add another stored value
ie, on the 'Store Lay BSP' rule add another stored value to store the BSP plus 125% and name it 'laybspmax' (orwhatever you want)
Then add another condition to your lay bet rule to test the LTP is less than stored value named 'laybspmax'