Well. For some skills, 1:1 isn't as horrible as it sounds at first.
Sure, epic has faster skill gained, but the vast majority of time spent skilling on Epic requires you to skill at higher Effective skill level, and at a slower rate due to this curve than if you skilled at your actual skill level.
For example, a skill like shieldsmithing or leatherworking, which I have reached 90+ on Freedom already, on SBCoC, usually goes a bit like this.
On Freedom, SB and CoC: 3 points per hour at 50 skill range, gradually decreased to 1 point per hour at 70 skill. Finally, about .60 skill per hour through the 80's and .20 per hour at 90. This is rough math, but I've grinded many skills on my account Deathangel to 90 and most of them take this similar rate of progression on Freedom. That's my freedom grind progression.
Now consider grinding those same skills on Epic, SB and CoC: my actual 50 skill 3pts/hr on freedom initially becomes something like 75 effective skill due to the epic curve. That means i'm gaining about 1pt/hr at 50 skill due to effective curve... however, I'm also benefiting from the Epic skillgain (x3), so that Epic 1pt/hr at 50 skill becomes 3pt/hr at 50 skill, on epic with SB and CoC. That means i'm skilling, using the same methods, 1:1 with what I would be gaining on freedom for 50 skill. The curve cancels out with the skillgain boost for 50 skill range on skills like mining and imping skills (carpentry, smithing,tailoring). Conclusion: throughout the 50 actual skill range, 1:1 is a fair conversion ratio. Now let's consider the same scenario but at 70 skill range:
At 70 actual skill, on Freedom, I typically get 1pt/hr with SB and CoC. Most skills in wurm progress this way, with a few exceptions like prayer, meditation, channeling?, etc.
So let's compare my 1pt/hr Freedom skilling to what I'd be getting on Epic (again, SB+CoC).
Converting 70 range Freedom skilling to Epic, Firstly, the epic curve makes me gain slower because 70 actual skill ---> about 90 effective skill on Epic. So instead of gaining 1pt/hr on epic like I do on freedom, I would gain at the 90 skill rate of (roughly) 0.2/hr (again this is with SB and CoC). Initially, before the x3 Epic skillgain buff, I am going to be gaining at .2/hr at 70skill on Epic which is much slower than 1 pt/hr on Freedom. Now we apply the Epic x3 gains effect: .2/hr on Epic at 70 skill goes up to .6/hr at 70 skill on Epic. That means, I'm getting 0.6/hr for most crafting skills on epic at level 70. On Freedom, I would be gaining actual skill at a faster rate of 1/hr at level 70. This means that for the 70 actual skill range, 1:1 is NOT a fair transfer ratio because skilling is faster on Freedom beyond 50's. For imping skills then, it is slower to skill on Epic than on Freedom beyond level 50 (approximately, I could put effort into exact cutoffs if devs wanted help implementing a fair conversion ratio). Note: This comparison is for most skills in the game that progress like imping skills (carpentry, smithing, tailoring). An easy comparison can be made for other skillgain types, it will just look a little different.
Now lets consider the early skilling (sub 50). In this situation, it is faster to skill on Epic than Freedom below 50. Take 30 skill for example. 30 actual skill on freedom is going to be faster than my 3pts/hr at 50. I can't remember exactly what 30 skill with SB and CoC is like, I'm gonna use 5 pts/hr as a reasonable guess. So 5pts/hr on freedom for 30 skill level.
Now we consider leveling at 30 actual skill on Epic. The curve makes 30 skill act and look like 50 skill. So instead of gaining 5pts/hr on epic, before applying the x3 gains, you're looking at 3pts/hr. Now we apply the x3 Epic gains and that becomes 9pts/hr on Epic at 30 actual skill. It's almost twice as fast to gain skill around level 30 on Epic, than on Freedom. So a 1:1 transfer on Epic-> Freedom at level 30 is NOT fair, but in the opposite way that 1:1 is not fair beyond 50.
Is there a way to convert Fairly, going both ways? Yes, there is. How? We can linearly approximate this shift using a few simple formulas for each 10 point skill range so that each skill is adjusted equivalently on transfer between the clusters. For example, 5 points gained on Epic at level 30 would translate to 2.5 gained on freedom at level 30, since last portal transfer. If I get blacksmithing from 30 to 35 on epic, then when I return to freedom I should have about 32.5 blacksmithing. If I go from 50 to 55 on Epic, I should have 55 when I return to Freedom. If I go from 70 to 75 on epic, I should have (1/.6)*5 = 78.33 skill when i return to freedom. That would be FAIR transfer ratios, or close to it based on TIME SPENT. That's using a linear piecewise function that has different ratios for different skill levels and it could be defined for as many intervals as we want to make it as fair as possible, but the result of a bunch of small skill range ratios would just be a good true function that represents it perfectly, some kind of exponential function that I could solve for if we wanted it.
This was written with respect to imping skills. Some skills work differently and deserve their own discussion. I'm just illustrating a fair conversion ratio for different skill levels that represents MOST important skills in the game to make it very plain and obvious that it can be done and that this post took me only 15 minutes to think out and write and that a happy, mostly fair solution can be drawn out in less than 1 full day of effort for all skills in the game if the right ppl are working on it, and implemented the next day.