bug about ALT and SHIFT casting

ln League of Legends, we are allowed to change to key settings. By default ALT + Q/W/E/R is set as self cast and SHIFT + Q/W/E/R is set as smart cast. However, I changed ALT + Q/W/E/R as normal cast, but I found that there is a little problem.

For example, after pressing ALT + Q, you need to press the left key of the mouse to activate the spell. The problem is that you need to unloose the ALT, so that you can press the left key of the mouse to activate the spell, otherwise, there will no response if you hold the ALT. But if you set it as SHIFT + Q, you don't need to unloose the SHIFT, you can press the left key of the mouse and activate the spell immediately.

So. I think the ALT should be fixed as like as the SHIFT.