Inserter research gives +0 at all levels.
https://drive.google.com/file/d/1PRpXSYZLIasRStoaRnFGINtqQ4cGWJD2/preview

Bot Cargo research gives +0 too.
https://drive.google.com/file/d/1xzYfGI3S1IU_QMl7Nu1-kw3mhtVCP6Rw/preview

UPD: Probably fixed screenshots

I cant see the screenshots.

The inserter tech is because its +0.5 wich i found out is not good idear but it still round to +1.
For bot cargo i cant replicate . it always give +1 or +2 (infinite one)

Ok, my bad, misunderstood.
But i made an investigation.

Bot Cargo Size 8 gives +2 (written idk exactly) which summed up to +9 in my game(if written = real).
Bot Cargo Size 9->Inf gives +0 (written)
I've researched 9-11(3 levels) and now i have +9.6 Cargo Capacity in the Bonus Tab.
Seems like 3 levels given me +0.2 each.
Conclusion: number is lower then you remember? But i guess +0.2 works with infinite tech.

Non-bulk Inserters.
Vanilla Tech is researched so they have +2 bonus.
Each modded tech gives +0 to non-bulk inserters on paper. Guess it's rounded down though.
I've researched modded 8-11 (4 levels) and now i have +4.1. Weird number, but its close to yours +0.5 so its okay.
Conclusion: Works.

Bulk Inserters.
Vanilla +11.
Modded Inserter Capacity Bonus 8 gives +2, sums to +13 is what i got.
Other techs don't give bulk inserters anything.
Is this intended behaviour?
Conclusion: 50/50. But basic inserters would become better then bulk in long term, so tilting to missed including bulk inserters in all techs.

tested on fresh install with krastorio2 ... my mod is not 100% compatible with krastorio . (some tech progresssion are weird)
good news i update the code to make it more compatible. v0.4.0 (also some tech balancing for krastorio)
bad news was not able to replicate your screenshot , so maybe a other mod that modifies robot tech is either limiting my mod or overwriting it.