already got a perfect response on jmtrad’s comment but if you wanna hear it from multiple people then:
i got both game versions and i assume the compressed version being lower quality must be true but i cant tell at all, so i just kept the compressed version and deleted the other to save space. (took me like 4 hours to download the big one 💀)
as for training, i think i already answered your comment once about this, its not that big of a deal and like jmtrad said in the other comment you never lose options, tho depending what you chose to do FIRST there are some scenes that can change, like getting the option to go to the party on the MC’s female form, but you can train every time first and still get this options easily.
The reason training first is recommended is because there are a few points in the game where if you didnt train a certain amount of times by the time you reach them, the game is gonna kick your teeth in with a dead end that can only be avoided by having trained a certain amount of times, but i think those are actually pretty hard to get on accident unless you completely ignore training. it never happened to me anyway ¯_(ツ)_/¯
Otherwise just train once, then do something else, then train gain, do something else, repeat ad infinite till the game no longer lets you train for a while.