[U-Boot] How to recognize need for new configuration

[David Nelson]

good morning/afternoon/evening

I have long been aware of my current project's implicit requirement of
building a custom bootloader with repeatable and consistent results, and as
such decided thatI would use U-Boot.

That decision was made months ago however I am still without a bootloader
for my target. This is for a couple reasons that I Sincerely hope can be
addressed within the not too distant future.

The first being Apprehension, this is simply due to a lack of knowlege. For
instance I have absolutely 0% of a clue about how to tell if a device is
even capable of having the existing boot loader binary replaced permanently
by U-Boot. For example, my Samsung galaxy tab pro 10.1 picassowifi built on
the exynos 5420 SOC, board name seems to be UNIVERSAL5420, what I DO know
about this device however is that the revision is r2p3, Architecture ARM
Cortex-A15+ARM Cortex-A7, with the Mali T628 GPU, with 1.7GB RAM available
to the CPU and 11.6GB flash available. And with existing facilities I am
capable of dumping any/all of the apparent 24 partitions to files on my
desktop and analyse with a hex editor. I am almost finished programming a
disassembler for static analysis of executables themselves to further
understanding of the underlying system. But im still afraid that i will end
up doing something  inherently stupid and seemingly obvious... and then
ending up with a nearly Letter size paperweight..

Secondly I favour where possible using a prebuilt version of a tool until i
understand it fully and have  deeper knowledge of the requirements/features
associated with tools of that type. at which time I can then develop my own
or contribute to an open project.

But it seems that no matter how I have approached the problem to date, I
always end up with an equally useless, albeit slightly larger pool of
resources to pull from..

TL:DR;

Is anyone able to offer up a shortlist of "If you do this, you will have a
paperweight" type  guidance?

And, How does a person go about determining within a small margin of error,
whether any existing configuration/board is appropriate for a device,.

thanks in advance,
David Nelson