That's a really interesting reason and I'm glad that you decided to share it with the community. It will definitely be helpful in the future, if anyone else comes across this problem!
In terms of calling multiple DLL's, this is allowed. Reason being, a DLL call can be considered to be a type of sub-VI that calls code from another language, in to LabVIEW. As a result, it is fine to use multiple DLL calls.
ShalimarA | CLA
