I have been testing safe methods on multiple different accounts, I have created over 40+ accounts with Origin Basic/Premier and have collected results on what triggered a ban.
What I have noticed is that during March - May, Instant Win was not detected and I could use it multiple times a weekend league / rivals with no ban. My most recent account was banned the next day for using Instant Win ONCE.
Instant Win v3 / Instant DC - I would say this is detected in any online mode now, using this more than once in Rivals/WL will almost guarantee a ban.
Club ID / Country ID / Skills / Weak Foot / Traits / Timed Finishing - Safe for the Elite ranks, this is risky in T100 as I have been banned for using these and these only. Do not spam 5* skill moves and timed finishing every shot otherwise it will get you banned.
WL Matchmaking - I believe this to be completely safe as long as it's used responsibly, if you are 10-0, don't be searching WL Matchmaking with 0 wins, I would say it is safe for T100 as long as you don't breach -5/-10 wins on each game, so if you are 20-0, don't search for anything below 10 wins at the lowest.
CPU v CPU - I used this for a full month on one account in Squad Battles, I got banned on the last week and it was a perma ban first time, no 7 day. In the ban email EA specifically mentioned "using modified clients, tricking the game into thinking you’re playing matches when you aren’t" which makes me believe that it is possible to be banned for CPU v CPU. Therefore I would say it's not worth the risk because Squad Battles rewards are awful anyway.
WL Info - This is completely safe no matter what you do with it, you can continue to leave games until you find someone with a bad record and it will be fine.
Some other stuff to mention:
- Just because my test accounts got banned for using this doesn't mean your account will, it all depends if their anti-cheat measures manage to capture it.
- Despite me mentioning that some things are detected, I would say everything is safe in moderation. I managed to use 2 Instant Wins every WL for 3 months straight in the Elite ranks with no ban, others got banned for using it the first time.
- Generally, if you use some sort of DC cheat in Rivals / WL and get a ban, it will always be a 7 day ban first time around. This is because the anti-cheat doesn't know if you're using a trainer to force the DC or you have just found a WL no-loss glitch for example, which is why the bans are lenient. If you use something which makes it obvious that you are using a trainer (CPU v CPU, Skill Moves / Weak Foot etc then if this is ever detected it will be a permanent ban every time)