Worth a try, but in my experience bunched Maggots or Casters (joint first choice baits) catch the best Crucians, followed by 4mm pellets as a distant second. Problem being as you have identified, these are great Roach baits too. Add to that an 18 or 16 hook and you are asking for loads of small silvers.
Personally I like to find a peg that's nestled between two lily beds. I look at it as if there are three areas like a clock, 10-12-2.
I feed into 12, normally brown crumb, casters, dead Maggots and some micro pellets in the hopes of drawing the brave small fish to there. I take turns fishing 10, 2 and beyond 12 all about 2-3ft from where I'm feeding in 12.
My theory is that the bigger more wary fish will sit here and pick up bits, so while I keep feeding steadily in to 12 I trickle tiny amounts of hook bait in to these three zones as and when I'm fishing them. I still get some tidgers but I also pick up the expected quarry along with bigger roach.
It's one of the only times I will actively choose a dirt cheap whip over any other tackle and I will fish it dead bottom with a telltale shot close to the bait or sometimes I go a little off bottom of it's warmer. The float is the lightest pole float I can get away with, weighted right down so it's just showing.
My alternative to this is an old cheap and soft green hollow glass "boys" rod which I have had for years since getting it from a car boot when I was about 10 for I think 50p I pair this with a little Strike Right Hydraflow "pin" that was also under £1 from memory. I use 3lb line straight through and little home made common reed floats.
The whip is more effective but the old green rod and rubbish pin is loads more fun.