I think you can, as long you settle the outstanding bills before switching.

Downgrading plan nowadays is relatively easy, even their CS on Facebook can do it pretty quickly for you.

I think it is possible,but u might need to pay the advance fee for every plan changing?

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5G video-streaming is being throttled.?

Previously, for the low-end 4G phone plans like GX30/38 and GX50/68, video-streaming was initially throttled to SD/480p or 1Mbps, as per the T&C - later (around June 2020) it was increased to FHD/1080p or 3Mbps.
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Afaik, fast . com is owned by Netflix and is used to speedtest video-streaming. Most low-end 4G phone plans limit video-streaming speed, eg can't get 4k/2160p/25Mbps video-streaming speed that is needed for large >54" TVs or 29" monitors. This may also apply to low-end 5G phone plans when the 5G Trial period ends.
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U98 comes with 1TB data that can be fully hotspot? Also what’s the experience of 15GB data roaming? I went to HK with a friend in July, no issue with my Digi roaming but she cannot connect on her U data roaming, ended up she bought a local SIM from 7-11.

Recently Digi changed the data roaming rule so I don’t really like it. Since I travel very often and I like the free data roaming. I feel like getting a U98 plan just for data purposes.