Since you are asking for opinions..here is mine
ECU programming is legal,
An increase in boost is legal, if it's an indirect result of an authorized modification
Directly changing boost or turbo controls is illegal.
When looking at the PCM's tune, these tables may indirectly increase boost, but they do not directly control boost. They also influence throttle, timing, etc. Changing these would be legal.
Any change to these tables would directly control boost. Changes to these tables are illegal