3.8-4.2oz. seems to be the magic number for my cues, my taper. A little lighter or a little heavier is ok if it works out well, but usually the best are 3.8-4.2. Heavier or lighter than that & things seem to go a little dead. It's all about harmonics & balance to density & dynamics ratios. I haven't pinned down a magic formula but have gotten very close.
As for sugar marks, if you are using sugar maple for your shaft wood, well it only makes sense that it have sugar. Maple that has no sugar worries me, and I actually avoid it. Every cue I build, no matter how fancy, is intended to be played. That in mind, I want my sugar maple to be healthy & full of sugar. The more the better, IMO, but it's not always easy to find. And when it is loaded with sugar, it's ugly because of all the little red/brown hair looking stripes all over it. I have personally noticed a, not insignificant, difference in tone, flex, & memory between clean wood & sugar loaded wood. For my own personal cues, and cues for folks who ask for them, I use ugly sugar loaded shaft wood. The ugly lines bother some folks & there's nothing wrong with that. Just gotta be picky about finding a cleaner shaft that still carries all the playability characteristics I look for.
I have been scouting, cutting, milling, and drying maple for shafts and have learned a lot more than I knew when I was buying wood. I thought it would be easy picking trees & loading up on great wood. Not so easy. The yield with trees is relative to the yield with shafts. It stays pretty constant through the process, which is about 30%. I cut trees that look awesome, like a giant straight shaft growing from the forest floor. I cut it & mill it only to find that it's not the quality I knew it should be. I cut the tree growing right next to it, which looks exactly the same with exact same conditions, and it'll be a gem. So far, the only constant truth I have found in MY cues, is that the shafts with sugar are the best, & 3.8-4.2oz is the weight range of the vast majority that have all the criteria I look for. Sometimes I wish I was ignorant & not curious. Then I could just buy shaft blanks from suppliers & make cues with what I got, never knowing of something different or better. But that's not me.