This isn't really a question as such, more an FYI, as it might be useful for some.
I can't vouch for SpinTels customer service as I'm not yet a customer of theirs, but I've been looking at 4G Home Internet plans that can be used between multiple residencies (Optus, Vodafone, and likely other ISP's prohibit this), and SpinTel appears to be one of, if not the only ISP that allows it (confirmed via online chat, however if anyone out there can attest that this isn't the case, I'll update the post). If you know of any other providers that offer this, feel free to include them below.
Eg. 4G Plus 500GB plan (speed up to 100Mbps, Optus network) $59.95/mth (currently promo $49.95/mth for first 6 months).
It appears that the modem (Huawei B628) is mandatory and not optional. You can purchase it outright for $210, or rent for $7/mth (however according to the SpinTel rep, no matter how long you rent for, you're required to return the modem when you cancel your plan, so I'll likely be purchasing outright if I decide to proceed).
depending on how much data you need, you could get two 1/2 price optus 4g mobile broadband data plans and the data is pooled between the two, eg 200gb pooled between two sims for $60/month. discount lasts for 12 months
or you could get the optus 4g home broadband unlimited data for around $59/month which includes device repayments
actually the unlimited 4g home broadband appears to be a new deal. it used to be 500gb for $59/month
edit: the 1/2 price data plans seem to be gone