Hang is not recommended to use in business component as the business component/adapter as the component or adapter will be blocked for that specified time.
However I would suggest something else in your code, to use Read($zutil(96,39)) instead of fixed value. $zutil(96,39) contains the number of characters that a String can hold. If Intersystems increase the number of characters for a string in future it will automatically take that maximum characters .
This thing happend with me before , i reported this in one WRC . This was solved automatically after few days. So i asked the engineer not to take any action on this as i thought it could be some connection issue from my end. I guess there is some issue with this but it was auto solved for me. I would suggest create one more connection with a different name the new connection should work.
I used "cuk/display=none" as flag and that solved the issue.