The primary motivation cited is lowering block orphaning
The place do you see this being cited?
AFAIK, the motivation is to cut back the sources required to run a full node which has nothing to do with lowering block orphaning. Moreover, the scale of the UTXO set does not likely impact block orphaning that a lot, particularly with compact blocks and FIBRE permitting blocks to be relayed with out being totally validated.
My private fullnode doesn’t care about if the UTXO is fetched from disk and takes time to confirm. (as lengthy it is properly beneath 10 minutes)
Your node doesn’t simply want the UTXO set when verifying blocks. It continuously wants it to confirm the transactions that it receives. Your node doesn’t simply sit idly doing nothing between blocks, it continuously receives transactions, verifies them, and relays them. If entry to the UTXO set is gradual, then verifying these transactions can be gradual. It additionally signifies that your laptop could also be devoting lots of additional sources in an effort to attempt to course of transactions shortly which can impression its efficiency in different duties should you use your laptop for greater than only a Bitcoin full node.
1) Is there another purpose for analysis behind UTXO set dimension apart from block-orphaning?
As talked about earlier, block orphaning is admittedly unrelated. The primary purpose is to maintain the price of operating a full node down to permit full nodes to be run on as low finish {hardware} as potential (e.g. a raspberry pi) in order that there are extra nodes. Having extra full nodes is healthier for the community, and holding the scale of the UTXO set small helps enable for decrease powered {hardware} for use for full nodes.
2) Straight associated to the primary query, is the UTXO set dimension actually that essential for non-mining full nodes?
Sure. All full nodes want the UTXO set in an effort to validate transactions. If the UTXO set is just too giant, it turns into dearer to retrieve knowledge from the UTXO set which thus will increase the prices of operating a full node.
Presumably you do different issues on the pc that runs your full node. You don’t need the node to take up the entire sources of your laptop, in any other case you would not have the ability to use it to do different stuff. A part of holding the node performant is to cut back the scale of the UTXO set.