change to hotlink red for 1 month, then change back to hotlink flex

yes, this is what i did 

Dunno how to comment, for me, I don't see any difference.

Disclaimer: the above statement is based on my "feel" and "experienced" not measured using speedtest whatsoever 

Anyway, the hotlink flex data is significantly lower than Maxis MOP (I believe u comparing to this), so, automatically you will be kedekut, try to preserve your data to prevent it run out before next refresh/ billing cycle  , so, this also limit the data usage time to test kau kau 

But one of the maxis agent told me we can switch.. in fact, i am planning to switch too next week..

if cant, i just port out of maxis and choose other telco

Only rm60 plan? if rm30 or 40, is it possible too?

I try before, RM60 downgrade to RM40 and then a month later upgrade back to RM60. Just the hassle is you need to call to perform the change and cannot be done via apps.