Conditional and Subjunctive in (Neo)Quenya

Tolkien's highly fascinating Early Qenya Grammar in Manuscript in PE14 devotes a page to The 'conditional' or subjunctive, in which he says:

"This is not expressed inflectionally but by particles, nai and ki, of which nai represents remoter possibility ('might'), ki (nearer) 'may'.
The pure optative is also often expressed by nai, or naike combined, at head of wish." (emphases as in the original)

He also gives some examples, such as

naike hi-tule 'would she might come'
hi-tule nai 'he might (possibly) come' or 'be coming'
hi-túlie nai 'she might have come'
hi-tule ki 'she may be coming, may come'

At this stage 'if' is translated mai, and it is stated that in conditional sentences ki/nai is usually in the main clause:

mai ni-tuluva, tu-tuluval ki 'if I come, they will come_

Given what (or rather what little) we have seen so far from later conceptual stages about the conditional/subjunctive (use of nai in Namárie, the (optative?) na + aorist/future constructs in Ataremma, the conditional phrases with cé in VT49 come to mind, are there any more?), can we surmise (pending publication of more stuff) that similar rules apply in later stages, or that we can apply similar rules in NeoQuenya? So transposing the phrases above:

nai tuluvasse 'would that he/she might come'
tulesse nai 'he/she might come'
túlesse nai 'he/she might have come'
tulesse (tuluvasse) cé 'she may be coming'

and extending

tulumnesse cé 'he/she would have come'

Is this conceivable or utter bollox?