This is most likely completely unintentional, but whenever a player is downed on top of the obj- the ‘help up’ prompt blocks the obj tool prompt.
Help up blocks obj interaction
like everything using “action key” when there is 2 actions then it’s a pain in the ass …
Already mentioned before, I hope some fix
While that priority might fix it for some moments, it still is not good. We will still End up Doing the thing we did not want too. Separate Keys are a must, or any other way to distinguish what is going to happen next. Maybe aim at the body or obj - to differ.
Exactly. Especially in the scenario of wanting to ‘help up’ an Engineer for an objective that is completed significantly faster with an engineer tool for example.
I’d hate to be repairing something at an agonizing pace when it makes more sense to bring up an engineer to do the job in half the time, even with the ‘help up’ time added in. And if you think about it, dead engineers are likely to be blocking such an objective most often.
Takes 5 seconds to help up and 5 seconds for an Engie to diffuse with a little gap in between whilst he whips his gear out, whereas diffusing without an Engie takes 10 seconds. 
I don’t disagree with the premise of not wanting the game to “do the wrong thing”, but in your example the faster way would be to diffuse it yourself, although the safer method would of course be to pick the Engie up, but of course it’s all very situational and dependent on spawntimes, player positions, numerous other factors, you could very well have to use either in different circumstances.
Rather than one taking precedent over the other why not do something like instead of a having the “press F” text in the HUD have an “<F>” IFF over each intractable object than appears when you’re in range. This way you can have multiple "<F>"s (one for each object) rather than a single “press F”, because the only way to know which “press F” is going to interact with is for more text, “press F to disarm”, which is never going to be as pleasurable a UX as a single icon for each interaction. With IFF’s you can also do clever things like making sure they are always spaced out by minimum distances and contextualising which IFF relates to which action by having the active one (i.e. the one your crosshair is nearest to) highlight itself and highlight the object it’s linked to.