Oh Lordy no. FLEx is just the software I’m most familiar with, so it jumps to mind. I was thinking broadly in terms of “features I want in a ling annotation app”!
There’s no way (to my knowledge) to search across notes fields in FLEx. But what I’m thinking about specifically is that the search results are just a clipped preview of the text around the example, which may not include a preceding asterisk. This would make it difficult to know (at a glance) whether a particular sentence is grammatical. To be good a fool-proof, I’d want it to be very obvious when an example is ungrammatical. Otherwise, a user might search for two morphemes, see they co-occur in an example, and conclude that’s grammatical!