Posting here again after sharing some thoughts in the Aura proposal.
Broadly speaking, I think it might be too early to worry excessively about which approaches are acceptable, how much control individuals should have over a protocol pooling funds to acquire veBAL, and overall what a healthy solution looks like. Perhaps a saner initial approach would be to be permissive and let all of these systems develop and grow, monitoring them and only potentially acting if it seems like they might become a threat in some way (which, even assuming malicious intent, I don’t expect would happen soon).
With that in mind, and given that Tetu is not a brand new platform, I don’t see much reason to not let them participate. If people are concerned, then maybe those could be addressed with risk mitigation measures such as caps on how much veBAL untested protocols can hold, or agreements on deadlines by which certain measures must be enacted (e.g. no centralized control). That discussion seems a bit out of scope of this proposal though.