Hi sillyme,I don't see particular depth except there is one sensation with it and it translates to loyalty/commonality about a type of issue - like a mutual consensus in one area and it could be about roles.
There is another description to the relationship and the MC/Mars is the focal point. Its not so much a depth as an intensity that has a hardness to it - like a severity of drive to prove some of their mutual consensus. Even though platonic, there seems to be some kind of having to prove something about the nature of the intimacy and connection. A scenario would be, we're not gay but we like being together and there's nothing wrong with two people of the same sex forming a close relationship that is essentially gay but without the sex - something like that would fit the nuances.
There is pain in a lack of fulfilment of large chunks of relationship ideals on both parts and when I look for this it is in the Uranus square to the 8th house planets. Neptune on the 5th ruled by Saturn in Sag in the 3rd and Neptune is in contact despite the considerably wide orb of opposition to Jupiter. So again a sensation that there is not so much fun as would be liked because of feeling somehow that as a couple you miss the mark in proving something.
Moon is tied comfortably to the ascendant and from the 8th house, which can indicate living closely or a propensity to tie lives together because of the emotional bond.
The indicators of pain, in my thinking are Venus - due to attachment, Moon - due to dependency/emotion, Saturn - due to restrictions/lessons, Chiron - because its chiron, Neptune - due to lack of fulfilment of self, Uranus - due to feelings of disconnection/estrangement/aloofness, Pluto - due to deep psychological issues.
When I look for pain, Saturn (3rd)and Uranus (5th),aspecting the Chiron-Moon-Mercury (8th), feels painful and distressing - like an out of sync feel - like you don't quite get the locomotion between you - so in a platonic relationship it would translate as a lack of enjoyment.
Mars on the MC aspecting Neptune, and as said, Neptune's scenario with Jupiter, gives a grating feeling that might manifest as trying to prove but could also end up coming across as angriness as a couple, and in aspect to Pluto may come across as a sarcastic crudeness in some of your responses.
Moon conjunct Chiron in composite, I feel, tends to attract static environmental/atmospheric 'fluff', which can play out as being victims to things going on around you - so an example might be, a terrible wind that blows debris that smashes your window; or walking down steps that either the rail finally breaks, or the front of a step crumbles or breaks away.
The relationship could last but there is a sensation of hollowness as mentions like large missing chunks that have sort of fallen into a funnel. So kind of sensed that the ideals of the relationship or important facets are there but just somewhere else - like they have fallen into something - perhaps Vertex quincunx Node is partly responsible.