I did read the criteria you listed. My serious question to you is that if you include every village and town, are there any cycleways left that wouldn’t fit the criteria. Are there cycleways that lead to nowhere?
A final suggestion from me: if you are only concerned about visualization and not about routing, couldn’t you solve the problem without any additional tags or changes. Namely: just make your own map where all highway=cycleways are always drawn with a thick blue line. You wouldn’t even need to filter out cycleways inside cities, since at very high zoom levels they will turn into a blue mush anyway. Ditto for the gaps: at high enough zoom levels, small gaps will become indistinguishable.