Ont guys tend to be more stringent on rules and regs cause there is so much that can go wrong.
Aside from that a big not to all who have a CA P90 to definitely replace your hop up rubber as The TM P90 is supposedly to have a very legendary hopup mechanism above the rest and the CA P90 is the clone of that wonderful hop up unit.
I took it apart and inspected it and from what I can tell its quite close to the TM P90 hop up unit except the fitment on that piece that holds the wheel in place seems to be a fraction of a mm off. But that I do not think will affect it much
ALL CA P90 users
CHANGE THAT HOP UP Rubber
Its way too hard and it does not give much hop even when placed on maximum while I remember the TM P90 gave a lot of hop up. So I believe changing that hop up rubber can get you closer the the TM P90 one.
I miss my TM P90 but the CA P90 being worth half and it is not a bad gun thats for sure. A few minor issues but can be fixed. But I would say not the best out of the box gun like the TM P90 would be
Source: On why the TM P90 is a legendary hop up unit