I confess to being something of a maverick within the Heathen community (a shock, I know). In my rune-work, I do not use the Elder Futhark of 24 runes. Instead I use the Younger Futhark of 16. This was not a choice made lightly, or out of caprice.
That the Elder Futhark was used by the early Germanic peoples is beyond question; we have archaeological evidence that seals that question convincingly. So, too, we know that the runes of that Futhark were used for magical purposes; Dr. Stephen Flowers' doctoral thesis (subsequently published, and which I have had the wonderful opportunity to read) makes a very convincing case for such as well. However, I still feel that one thing is missing that makes the use of the Elder Futhark in modern magical practice somewhat problematical.
Specifically, we do not know the names, let alone the esoteric meanings, of the individual staves of the Futhark.
Bear in mind that our knowledge of the historical esoteric meanings of the various Futharks comes to us from the various rune poems. There's an Anglo-Saxon poem, an Icelandic Poem covering the Younger Futhark, and a Norwegian Rune-rhyme covering it as well, and a few other bits and pieces hither and yon. Between them, they form a coherent corpus of esoteric meaning which is internally consistent for each Futhark.
Unfortunately, we do not possess any rune poem which covers the Elder Futhark from start to finish. What knowledge we do have, and which has been passed along in various books on the subject for decades, is a patchwork of meaning derived from a combination of the Icelandic/Norwegian poems and the Anglo-Saxon poem. Separated by centuries and oceans, they attempt to assume that the "missing" runes from the Younger Futhark had an identical meaning to those from the Anglo-Saxon Futhark. While this is certainly possible, it is by no means certain.
The problems of such a patchwork approach are obvious, and not the least confined to the notion that any given Futhark is intended to be a whole. That is, an encoding of the understanding of a given Germanic group as to the nature of the universe around them.
One need go no further than the second rune in the Anglo-Saxon and Icelandic poems. In the latter, the ur-rune is the mighty Aurochs, the ranger of the moors. In the former, it is drizzle, the cold wet rain. It is also, puzzlingly, both shadow and leader. The exact metaphysical impact of those meanings is beyond the scope of this particular post, but the point is made. The runes have different meanings in the different poems. (I should point out that the ur-rune is only one example of many; it is not an isolated case.) If each poem encapsulates the knowledge of its attendent culture and runological lore as a coherent whole, then how could we possibly make sense of a system of runes for which no such poem or other system of encoding is extant?
Many worthy folk and good scholars have made the attempt, and I by no means intend to diminish their efforts. Such a thing as the choice of a futhark for esoteric work is most definitely a personal thing, and if someone feels called to use the Elder Futhark with interpretations stemming from various sources into a whole, I will not gainsay them. However, neither will I follow them in the endeavor.