Default [Q] [Need recommendation] Wifi issue on 4.3

After upgrading to 4.3 [NE1] firmware through OTA, my wifi can't find many hotsport. The signal strength becomes very weak.
At the same location, my S3 can find 10 conenctable hotspot, but this note 2 can only search less than 3, and barely connect any of them successfully.

I studied a lot of solution at XDA, then I determined to root my note 2 and get it fixed.
Thought it's relative to KNOX security; so after root this phone, I
- install
- install script file to remove Knox

Almost refer to below thread

Doing everything completely and successfully, however, my wifi still runs not very well.

Anyone can provide recomemndation for me?

If changing modem will help wifi connectivity?

Mine is region-BRI /Taiwan/ revision (PDA: N7100ZSUENE1 CSC: N7100OZSENE1 MODEM: N7100ZSENE1). Or, shall I update my firmware through Philz-recovery to 4.4.2 directly? Any specific revision I can upgrade it directly?

thanks you all of your ideas!
Attached Images
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