The one feature I would like ETS to add is (paint) conversion ideas. I am convinced this would boost sales for manufacturers. So many ideas around but no one-stop place where to find them.

Six simple conversions - not for the button counter but close enough for me:

HäT WW1 Russian infantry is nearly identical to Bulgarian infantry.

HäT WW1 Austrians are used by many to fill in for WW2 Norwegians.

HäT WW1 Austrians can also double as Spanish Civil War infantry.

HäT WW1 Austrian heads on Redbox Boxer Rebellion Italian Bersaglieri and voila additional poses for your WW1 Austrians.

Airfix Commandos 1st type with headgear swapped for Adrian helmets can stand in for Spanish Civil War Republicans.

Esci WW2 French infantry can also be used as Spanish Civil War Republicans.

WW1 Germans with steel helmets look quite similar to WW2 Hungarians.