Well these days my tuner of choice is no tuner at all, and an unlocked ECU with the tools to do it myself. For example, some of my previous generation Triumphs (675R) and KTM (690 supermoto) I could just plug in TuneECU, install my new map, make any changes I want and be done with it. Easy and free.
These days however more and more ECU's are getting locked down so you have to use a piggyback controller. If someone has "cracked" the ECU sometimes you can send it off to get it reflashed but most of the time you have to use a piggyback controller. With the BMW 310, it's kind of a fringe bike. I doubt anyone is going to put in the work on the ECU.
As far as a piggyback controller, Dynojet does it well and if you have to use one there's really no reason to use anything else. You mention a "fuel enrichment solution" like you might be talking about the BoosterPlugs and other tricks that some people are using. The proper way to do it is with air/fuel mapping on a x/y table with revs and throttle position.
You can't properly control an ECU with a "PowerJet" controller
Real tuners map air/fuel ratio to a table.
Dynojet's Power Commander V also has the functionality of adjusting ignition timing, something that Bazzaz and many others do not have in their base units without an expensive add-on. So in summary, Dynojet is old, but it's also the most refined, and if you have to have a piggyback tuner it's the best choice.
The point of my original post is not to promote "stupid tuning options" for the G310GS. It's to help find a donor bike for Dynojet in Las Vegas so they can finally confirm fitup and get an official offering on the market. On the other hand, maybe they just don't care. These bikes aren't very common. If they really wanted an option on the market for the GS they would have bought a bike to work with.