It is obvious that this passage is very complex. Originally, it was a run-on sentence. Here in Helaman 3:29, the editors for the 1920 LDS edition emended the text by inserting the auxiliary verb may before lay hold. In the original text, the immediately preceding will acted as the auxiliary verb for lay hold, but the 1920 emendation makes will into a main verb with the meaning ‘wishes’ or ‘wants to’. One problem with this emendation is that it makes a minor change in the meaning of the passage. The original text expresses the idea that the word of God will lead the man of Christ to the kingdom of heaven. The use of may weakens the original meaning in this passage by introducing a sense of optionality.
In the original text there is actually one example of will may; in that case, 𝓞 is entirely extant and the reading is appropriate:
There are some other cases of “whosoever will” where will acts as an auxiliary verb and is immediately followed by the main verb:
The question is whether the sentence fragment in the original text for Helaman 3:29–30 actually needs to be edited. The structure is so long that it doesn’t seem to pose any real problem in understanding. In addition, there are other such run-on sentences in the text, some of which have been discussed previously. See, for instance, the case of Enos 1:1–2 (discussed under Enos 1:3).
Summary: Remove the intrusive may from Helaman 3:29 since this extra auxiliary verb makes a change in the meaning (although minor); the original sentence fragment is readily understandable and is consistent with other incomplete sentences found in the original text (some of which are still found in the current text).