I guess I'm quite confused as to your statement that Thingamabobbers are "too buoyant to use with midges". What does this mean?
Any indicator is used to primarily track your sub-surface offering, suspend your offering, and indicate whether or not you have a take. To state that one type of indicator is too buoyant is confusing when used universally as stated above. I used yarn years ago and they became water-logged, required regular floatant and did not cast well (my opinion) that's why I celebrated the change to the Thingamabobber. I use either the smallest size or next smallest size rather than the medium or large sizes.
Anyway, just a little confused by your statement. Enlighten me.