Angle adjustment for front seat base

[steviewevie]

I find the front seat bases a little too tilted back for my liking and so was happy to find that there is a lever mentioned in the manual to adjust the angle - then disappointed to find my car didn't have that lever.  I have standard seats, I think the extra lever comes with comfort seats?

Looking under the seats though, I did wonder if I could manually adjust the height of the front of the seat base. Has anyone ever tried?