Yes - JetBlue are quite clued up on this. I fly them frequently in and out of JFK domestically, and they are so much better at the gate than BA or Virgin (all style, no substance). So it's no surprise JB actually encourages travellers to use the TC security at Logan, knowing there is no Precheck at TE. With these recent additions to participants in Precheck there must be increasing pressure to add the Precheck service at TE. If BA is still lagging while others have access, it will encourage people to use another airline that does participate.
BA is quite a big player at TE with the A380 service at the expanded gates, so if/when they do join, there will be more need for a precheck lane at TE. Too bad it's such a cramped area - I suppose the two retail outlets (newsagent and restaurant) could be relocated without being missed very much.
I do wonder what the holdup is with BA joining? Perhaps BA (like some UK banks) would prefer to share as little info as possible with the US gov't so as not to irritate some of their "sensitive" low profile customers :-)
I do think the TSA needs to modify domestic Precheck to include frequent travellers at a lower upfront cost. They need a three-stage "triage" setup, with "Pros" "Experienced/frequent" and "Tourist" lanes. The Pro lane will be the existing Precheck (Global Entry, Nexus) who do the background check and pay $$$.
The middle frequent/experienced group would have the option to pay much less (say) $5 extra at booking and then join a self-funded "points" system. Every successful trip through security gets you a point up to a maximum of ten points. Any "problem" you create loses you some points depending on severity. You need five points to be in the lane. Or something like that. Needs no new equipment. The lanes are the same, just designated a bit differently. The backend systems software (and admin) would be paid for out of the $5 and a contribution from participating airlines.
The middle "experienced" TSA checks would be exactly the same as the Tourist lanes, but (at least in theory) the people in there would be both more familiar with the processes *and* motivated to not make mistakes.
In airports/terminals without Precheck, this system could allow the two experienced groups a possibly quicker trip through security. The current Big Orange Card process used at some smaller airports is a bit of a joke, IMO. Confusing and while it allows Precheck customers to leave their shoes and belts on and laptops in, hardly speeds the actual scanning as there is no distinct lane. And why not? Because not enough flyers participate (because it costs too much and they don't travel often enough - see above).