Had this exact some problem - very slow startup, especially as my supertrends began accumulating data. I was keeping a years worth of data for quite a few supertrends as the customer had requested that. So after a year of accumulation, the startup was taking on the order of 20-30 minutes before the Runtime would begin updating.
After close to a year of battling this, we finally figured out Windows Defender was the culprit. Upon startup Windows wants to scan all the project files that Runtime might be opening - including all supertrend historical data that apparently gets touched by PAC Display Runtime when it first starts. So we made exceptions for not only all Opto 22 program files, but also ALL of the project files as well. Startup is now the snappy result that I expect. I hope this helps.