Notbad.jpg your choice.. It’s a tad unconventional, but hey you seems to know what you want and don’t mind the shortfalls... So I wish you well and hope the Roku brings you hours of joy. 
Yep.. it truly is a unique choice. Man seems to know what he wants and I love it when one knows exactly what they want ..

Ah yes, like smartphones or cars.. there’s only so much faster one would like to go and eager to pay for. Why not consider the Beelink GT1 MINI 2? It’s no GT-King but it’s like a zippy mini-cooper..  Surely, feel the speed SoC bump without hurting the wallet much. If you get it, I strongly suggest going the custom ROM route.
It would help if you listed out your viewing requirements too. Can’t recommend proper without those.
I haven’t tried the H96 Max..This is the one with the Rockchip SoC right? Well for starters, I’m not a fam of RK chips. Strong personal preference stemming from a dev POV. So that alone would definitely rule it out for me. However, if thinking support? Best to stick with the likes of HiMedia, Minix, Xiaomi, Beelink, Wetek, Roku, Amazon, Nvidia, etc. Basically brand names that’ll stand by their boxes for awhile.

Oh yeah, same advice as Ken’s above... list our what you intend to use it for and how..

Ah for RM100.. Really kenot complain d.. Just have to accept what is and what isn't.. As for apps recommendations.. User futra has listed a few below. They should be fairly easy to find online. Just be wary of where you download em from ya.. Always first seek official sources, lest it comes with unwanted guests. 
Yep, as others have suggested... Can't exactly compare ehem app performance with those from big guns.. Nevertheless, apps like that should have access to decent servers. Depending on the title you want to watch. Fast servers may or may not be available to stream from. Particularly if the title is an older one and most of it's stream-able links have been deleted by the hosts (They do get a lot of take-down requests). Makes it harder to find high quality instant streaming links. UNLESS, it's p2p (this has its limitations too) or you have a RealDebrid account. I urge you to consider getting a premium RD account, as it makes a world of difference with such apps.

Alternatively, It could also be the MiBox itself and or Unifi... They suffered an undersea cable issue recently and iirc, the issue has been rectified???.. I've been reading a lot of posts about some throttling under TM's network. Now whether this is intentional or no choice? I can't tell. I've got TIME and can notice a difference in even browsing speeds between both. It didn't use to be like this.. But it is what it is now. Given the worldwide increase in media consumption. ISPs are being hammered 24/7 and as such, they have to adjust accordingly. Smaller ehem and free (premium users usually get much better performance) services are stretched thinner now too.
Yup.. I typically recommend a factory reset first too. Before uninstalling what I deem as crap. TBH, like you mentioned... One only needs a handful of apps and we good d. Only thing is, having options is still good. Some buyers are savvy enough and have the time to setup exactly how they want it, while others prefer setup to be done by seasoned others and they willing to pay for it. Saves them time and effort, true plug and play scenarios. Where I have issues, is from sellers who just throw in a lot of junk, just to list as "ships with xxx amount of channels, movies and apps". 
Hmmm... Gotta pick one to suffer.. Cuz typically, an Android box capable of Netflix FHD+ tends to be running ATV OS (Cuz Netflix requirement among others) and is setup in a way that the Astro Go simply doesn't like. Seeing as the Astro dosen't (yet?) offer an ATV OS app.....we can understand why... Then it's no surprise if the problems stock ATV OS users face when trying to use the Astro Go app, isn't to be expected. It's easier, if your TV has an inbuilt Netflix app you can use.. Then you can focus on just getting a better separate media player for other usage. Otherwise, it's just hard at the moment to recommend an Android box that excels at both. At least not without some "fooling around" involved. Last I checked, you could get a Beelink device plus a microsd card, slap CoreELEC onto the microsd card and dualboot into it..Install the Kodi addon and you good. You will be able to get Netflix FHD & DD+ audio (some say ATMOS even, i don't have the setup so couldn't test that) up and running in that config. How long this will last? I have no idea as it's an unofficial workaround. Then when you want to view Astro? You reboot back into the Android OS and launch that there. As you can see.. It's not the easiest method, but hey.. it works. The best is still to use a TV with Netflix app & external box confirmed working for Astro Go.