You can't talk in absolutes like that as everyone is different and will require a different dose. In regards to pharm vs UG 10mg avar is 10mg avar. So you don't need more UG avar than pharm at all. Well if your 10mg UG avar is really 5mg and underdosed then sure you need double. If it's fake you obviously won't get any results. Something is fake or real but you can't state if you require x pharm dose you will need y UG dose it doesn't work like that.
All of the people you likely gave it to in a clinical setting had never used it before and they were probably out of shape normal people so of course 10-30mg will make a big difference and help build some muscle. UG avar dosed at 10-30mg would do exactly the same thing. That doesn't mean everyone only needs that amount though. A regular out of shape person and a 200-300 pound bodybuilder who have taken many different AAS in the past are very different things. There is no 1 set rule in all of this.
In regards to the OP no orals don't just stop working but say 30mg avar is going to put on 8 pounds on you with your current diet then if you do that after 6 weeks you are not just going to carry on putting on more weight/muscle if you use the same oral. There is a ceiling limit to everything and you will have to increase the dose or change something else (increase protein etc) to carry on changing. Another thing most people stop respsonding as well as they get older especially if they run the same thing over and over. Moreover, if your physique develops singificantly in that time as well it may mean you require more to get a similar effect. It's very different taking 30mg as a natural weighing 180 pounds compared to taking 30mg 20 years later after 40 AAS cycles weighing 50 pounds more.