Hi, I've been overlooking rules and bug reports for a while and managed to get a few minor fixes implemented to Vale.
https://valeofeternity.wiki.gg/wiki/All_Cards
You might be the first person to ever try to Scorch an Aeris on a completely empty board in over 250k games since that is such an unusual interaction. Yes, you should be able to summon Scorch in that situation and copy Aeris. Is it a good choice? Not really since it is spending precious stones to score 9 for 9 instead of building up an engine, no real way to hit 60 points, but it is technically legal.
Scorch is the most bugged card in the game in its current state and many bug fixes around Scorch have already been implemented. It pretty much runs on spaghetti code. If you are trying to use Scorch optimally it will work correctly 99% of the time, but has some coding issues.
Most common "bug" with Scorch is when it copies Aeris. When scorch copies Aeris it should technically be Scorch that is looking at "other cards" to recover and therefore recover Aeris, not itself. There is a niche strategy of looping Scorch-Aeris with heavy stone production and stuff like Gargoyle that will Scorch-Scorch-Scorch-Scorch to victory. What should actually happen is Scorch-Aeris-Scorch-Aeris alternating.
The next common Scorch bug is incorrect summon eligibility like you are describing. This is where the spaghetti code comment really comes in. Scorch is annoying to code because it has to have every single possible option listed out separately, check for summon eligibility, and execute each one correctly. Some bug reports with Scorch and specific cards have already been fixed or thought about when coding. For example you are allowed to summon Scorch to copy a Leviathan (discard a dragon) as the only instant card when no other dragons are out because Scorch has been manually coded to know that it is a dragon, therefore it can copy Leviathan always. Leviathan/Scorch was fixed via this bug report
https://boardgamearena.com/bug?id=111724
On the other side you have the "empty board Aeris bug" like you are describing where Scorch does not count summoning itself for eligibility for Aeris like it does for Leviathan so it cannot be summoned. This bug occurs similarly with Forest Spirit and Young Forest Spirit being unable to be copied by Scorch when your hand size is 1 or 2 cards respectively.
What is likely happening is that the summon requirements for Aeris, YFS, and Forest Spirit were copy-pasted into Scorch's effect when it is summoned without adjusting the requirement around the cards already being in play rather than in Hand. For example to summon Forest Spirit normally I am sure the game checks that you have 1 open space and 2 cards in hand (1 being Forest Spirit, 1 to discard). However, when forest spirit is copied with Scorch already in play, you should only need 1 card in hand (the one to discard), not 2.
Please see these bug reports and comment and or thumbs up to make it visible. It would be nice to get another round of bug fixes to Scorch spaghetti code.
https://boardgamearena.com/bug?id=168519
https://boardgamearena.com/bug?id=121056