Speaking for Terminal B (and vague memories of our last international arrival into E), the Limo pick up point is a shorter walk than going all the way to Central Parking for the Uber/Lyft point, but it is still across the street (one drop off lane, I believe, in both cases) from either terminal building. The B pick up area for limos is under cover, inside the garage; I think E was open air so you'd experience any precipitation there.

Here's what the massport website says about it: https://www.massport.com/logan-airpo...ransportation/

Lyft can still drop me off at the curb, so I'll still use them sometimes towards the airport, but I'm not sure if only my need for accessible drop off makes that possible. In the morning, and if I'm traveling light (or have my teen with me to lug baggage), I don't mind taking Logan Express to the airport, either, because the waiting area in my suburban area is comfortable. (Standing at the curb to await a bus wouldn't work for me on the trip home.)

My husband used Malden Car Service when traveling for work a few times prior to the pandemic. Since then, as my mobility challenges have increased, I now use them regularly if I'm arriving later in the day when my energy flags. They've been reliable, but, of course, cost more than a taxi.
www.maldencarservice.com