Wizzair flew BOH-Katowice and Gdansk for a short time, easyJet flew BOH-Krakow and Ryanair flew BOH-Wroclaw. None of them lasted because the drop in Polish people living in the South was too significant after the boom in Polish influx of 2006 and 2007. Polish routes from the whole of the UK have somewhat fallen. But i still do believe Warsaw would be good from SOU/BOH. whether Flybe do it i'm not sure. Flybe were probably concerned if they went on the SOU-Polish routes that a LCC would do the same from BOH. But i think that is unlikely now so Flybe should be OK to explore. I would suggest 3 weekly flights with an E-195 118 seats. Having said that, Poland - UK is a low yielding market and it may be more suited to larger aircraft, lower fares.