4L60 and 4L60E are built from the TH700 design. The TH700 started out in first gear from a stop and always worked fine from about 1982 to 1993.
I shortened the TV cable by 1 click on my TH700R4 and that firmed up shifts quite nicely.
Also in the late 80s or early 90s GM pretty much dropped the high speed rearends like the 3.08 (gears I run) and 2.73 offering in trucks. So if you run 3.42s or 3.73 gears you don't really need 1st gear with an TH700 or 4l60E.
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, C5 front brakes, 4th Gen disc brake fbody rear end.