Anyone use usb modem 4g connect to their pc/laptop to use sim data? Does current sim block such usage?

Only if you use unifi AIR or Digi Postpaid 150 Infinite (which is already no longer available)

For others you need to ahem
FUP already stated no usage in routers
Somehow plan/sim that still work will use hotspot quota if available

Depending on Telco...
Need to try error...

Not all can work....
Sometimes okay sometimes cannot detect...

yes 4G kasi up non unlimited plan
digi best / live / broadband sim card.
any wireless broadband plan
sim card that don't have 'hot spot' thing
onexox

Most can't now especially the cheaper tiered ones on prepaid plans.

Even if they claim it's hotspot-able, it means the SIM must still be in the phone and you can only share it but turning on the hotspot feature not by inserting the SIM into a modem.

The telcos don't want to spoil their high priced fixed mobile plans with cheap prepaid plans which defeats the purpose. So to be safe the only mobile plans I can think of now which are modem friendly are:

Unifi Air Plan
Maxis Postpaid Family Unlimited RM99
Celcom Home Wireless Broadband
DiGi Old Infinite 150 Plan

Or you can try those quota volume based prepaid plans.

Unifi air and yes with data quota can. Yes unlimited cannot. But yes and unifi air have special band not all usb modem support. Maxis pantas plan with data also can, maxis next with unlimited and hotspot still can. I don't know if they have term and conditions allowed it or not but as i try now still can work with modem