i was thinking maybe its another mod problem but after turning off platformer and checking on new game bob inserter tech appears

Also having this issue; the inserter configuration screen shows, but the technologies are gone.

also having this issue (but with Quick Adjustable Inserters) and i think i've found the problem

the techs actually do still exist, they're just hidden. platformer has a function that "removes" (really just disables and hides) all technologies with no listed effects, presumably to easily remove any technologies that have 0 purpose due to the nature of the mod. this also happens to remove techs from other mods, including the ones from these inserter mods, because they don't actually technically have any effects.

Ran into this today too... Fixed it by exempting Bob's from the Platformer prune. Not elegant, but it works.

Unpacked %APP_DATA%\Roaming\Factorio\mods\platformer_1.0.6.zip, looking for the file \platformer-1.0.6\lib\technology.lua

Look for platformer.technology.prune function in that file.

The line that reads: if platformer.helpers.tablelength(technology.effects) == 0 then

Changed to: if platformer.helpers.tablelength(technology.effects) == 0 and not string.find(technology_name, "bob-") then

It is simply requesting any tech with "bob-" inside the name be ignored during pruning. You could extend/polish as desired, but I only wanted one mod.

Re-zip, ensuring you don't alter the base folder name, or zip name (e.g. _1.0.6 vs -1.0.6). Start game... I have only played an hour or so, but seems stable.