I tried that arma build 0.2.8 2008-03-08 on Mac Leopard. The first thing I saw was that all the text got huge again.

In 0.3 there's a FONT_SIZE_FACTOR that I can set e.g. 0.6 so all text gets smaller again. That same command doesn't seem to work in 0.2.8 2008-03-08 yet.

Is there any alternative way to reduce font size?

yep, i use
CONSOLE_ROWS 100
instead of 70 i think by default

console-columns