So i tried the tweak to switch on gpu as in xlinulx's post on droidevelopers:
Things you should do after rooting your Defy Mini xt320:D
Have had no trouble with display not timing out.
All good so far.
If i could only get hackers keyboard to w...
kernel: 18.104.22.168+ buildsrv@lxdex2 #1
Carrier/Country: PLAY Poland
Software version: TNBST_4_0A.21.2DRPS
Flex version: WE_PLAY_Poland_v8_0728_FLEXTNBST
Blur version: 10.33.45.XT320.Play.en.PL