If you have more than 20 symbols in truedata, incoming data slows down. They have a horrible speed of server.
I strongly advice you to not subscribe to Truedata for scanning purpose. Moreover, unless the data is requested by the chart, the data does not come. So, you would have to click on each of the symbol.
It is fine only if you are getting fewer symbols.
In case of global data feed, I would suggest only datapro2 which is amibroker specific. Others plugins also, I would say will have similar issues as Truedata.
Global data feed have a offer for zerodha clients. Provide your contract note. Actually, for a decent trading, you would need 50-60 high volume symbols. Also, not sure, why you would need both nfo and cash segment. They also have ACC19APRFUT.NFO. kind of symbols.