Thank you very much for your clear and rapid answers !
Adam : "I have never tested this with a large amount of keywords but I've just filled it with nearly 700 words and all the settings were saved properly and the plugin seems to be working fine".
1) The number of feeds with nearly 700 words is-it limited and if so, how many feeds with nearly 700 words for proper operation of the plugin ?
2) The number of feeds without keywords, is-it limited and if so, how many feeds without keywords for proper operation of the plugin?
3) Regarding thematic research articles in newspapers, can you give me an example to help me understand the purpose of the "Regular Expression Match." how it operating it ?