Making away goals count double is supposed to make away teams attack more. But it might also make home teams more defensive. Which, if either is true, should be easy to check by comparing european matches between teams in the same league with their domestic league matches. It would be good to see such data.
In a league, you always have the opportunity to spread out
results against one particular team over the other games.
Which changes the stakes significantly for most games.
UEFA KO ties less so : you have only the 2nd leg to rectify
any mistakes made in the 1st.
In recent times, the Citeh vs Poool and Citeh vs Spurs CL
KO ties have been belters, IMHO far above the spectacle
and resolve of the teams in their recent PL encounters.
In 2019 Spurs scored THREE AWAY goals in the KO stages
against both Citeh and Ajax.
Who did similar against either that season, at any stage of the CL ??
On that basis there are grounds for stating that the number of
away goals should be subject to a multiplier based on the UEFA
ranking differentials between the opponents.