Well I wouldnt say doctors are more trustful just because they are doctors, there arent many who continue studying after university, so their information is mostly outdated.
You are right that a 0.1% one makes a big difference to a 2.5% one.
So lets say it like this, if one has no history with stronger corticosteroids or erection problems then he can maybe use it without any problems, but one should be very careful.
Sometimes we can do things that are scientifically proven to be dangerous/counterproductive but yet they somehow do good things for us.
Jelqing for example; many see gains in length and girth and have no problems at all.
But in fact jelqing (especially with higher erection %) releases PGE2 which is very bad for sexual function.
Do you remember people talking about a "hard" flaccid? That's the effect of PGE2. If one gets a hard flaccid: stop Penis Enlargement immediately, recover and then start at a lower intensity.