For Maxis Postpaid Unlimited (the one when you have broadband fibre/4G in the same account),
FUP for wireless internet in 300GB/mth per whole account.
The counter is inclusive primary mobile, supplementary mobile, 4G home broadband, and 4G backup to fibre.

The recently revamped home wireless broadband up-ed its applicable FUP to 500GB/mth.

As at 16th August, I have yet to see revision of FUP applicable to the rest; principal, supplementary, and fibre backup dongle.

so i am not sure how it applies on an account if you have a higher FUP product (i.e. home wireless broadband) under same account as lower FUP products (i.e. primary, suppl, and fibre backup dongle).

yes, i also subscribed to maxis fibre.
(un)limited is amount of data.
(un)capped is speed of transmission.

the T&C of FUP of 300GB applied to WIRELESS usage of an account, not per line. that FUP includes usage of backup fibre dongle, home wireless broadband, and all mobile lines.

i read T&C on 16th they revamped the FUP for home wireless broadband ALONE to 500GB. i am not sure if the old 300GB still for applicable to the cummulative of rest of wireless products, or is it implicitly updated to 500GB as well if you have home wireless broadband in same account.

yes. unlimited amount of data.
the FUP affects speed of transmission.

no breakdown so far. not really achieving subscribed speed, but i made peace with self-blaming it on TM's scheming, and the cable being 3-sections from pole (pole to external roof, built-in roof to internal wall, wall to ONU).