I think all ncl clubs should be entered into the challenge cup. Bit unfair just the top 20 in my opinion.
Maybe div 2 and 3 teams go into preliminary rounds with community clubs, then 1st round the prem and div 1 teams enter.
Could maybe tie this in with the national cup so any team that doesn't make the 2nd round of Challenge Cup goes automatically into national cup?
Play the games on consecutive weekends or until end of feb or start of the summer season. That way teams are playing before the season, teams will have prepared for CC and it won't be just for a 1 off game if knocked out of CC untill mid march when season starts.