operation time open .dita with extendscript

Does anybody know why opening .dita with extend script takes much longer than the same operation manually. Can you suggest right parameters as i will overcome unnecessary stages during opening.

I get some issues - for example:

DITA+FM ERROR: Unable to locate referenced topic id: #id173KA60D03A/id185MM0L05HS

but I'm not sure that this might be the reason of delay.

Thank you in advance.