You are right that JR and appealing to SENDIST are 2 different things.
JR can be used for things such as the LA not complying with the AR process. Also for things like failure to provide the provision in the EHCP or unlawfully refusing transport.
Appealing to SENDIST is for challenging the content of the EHCP. Once the phase transfer EHCP is finalised, you will get the right of appeal. Even if the appeal window from the last AR has closed, you can appeal when you next have the right of appeal. If you need to appeal sooner, you could try asking SENDIST for leave to appeal out of time. It isn’t guaranteed but they sometimes allow late appeals.
It isn’t a matter of which is more direct. Rather which can be used for the issue at hand. This is because, for example, you can’t go the FtT route to force the LA to comply with the AR timescales, and equally you can’t use JR to challenge the content of the EHCP.
A Tribunal standard report isn’t irrelevant. Firstly, you may want to use it for Tribunal later on. But secondly, even if you have no intention of appealing, it signifies the level of the report. All reports should be good enough quality to be used as a Tribunal report. Sadly, they aren’t. Hence looking for a Tribunal standard report.
Just because it is standard practice, doesn’t make it lawful. Using the Y5 AR isn’t lawful. The LA knows this. Don’t believe it has never been challenged just because you are told that. LAs use that line to put parents off and make them feel they are being unreasonable. You can successfully challenge unlawful behaviour.
The problem with using the Y5 AR is there is a chance the LA may turn around in Feb of Y6 and say oh we can’t finalise the secondary placement we need to hold a review first. Yes, you could then take action, but it is a delaying tactic and game playing. This can sometimes be more prevalent if parental preference is wholly independent. This delay then means you can’t appeal straight away. Pressure on court time means the later a phase transfer appeal is submitted, the less likely it is to be settled prior to the start of Y7.
It also means parents have less time to learn the law (e.g. knowing they don’t have to complete the LA’s admission form, knowing they don’t have to state a MS, knowing they don’t need to state multiple placements), less time to make decisions on secondary schooling (especially important if parental preference is a wholly independent school who make decisions on who to offer places to later in Y6. Also important because some schools won’t speak to parents before the autumn term of Y6.) and less time to ensure B&F are right for phase transfer (including ensuring there is updated evidence where necessary. It can be the difference between having watertight evidence and not which is importantly since B+F=I). It means if parents change their mind in September (or October or the beginning of November) they then need to ensure the LA then actually follows the law in order to give them the opportunity to comment on the draft and state a preferred placement.
It means an AR must be held summer term of Y6. Unless of course the LA acts unlawfully again, as many do.
From the LA’s PoV, it also means the LA risks parents taking a case to the LGO or going down the pre-action letter/JR route.
Using Y5 ARs means the LA is likely to breach the statutory timescale for finalising the EHCP following the AR because it is unlikely the LA is going to finalise the secondary placement so early across the board. Delaying finalising frustrates parents’ right of appeal. And they are unlikely to finalise within the timescales with just the current primary named then go through another AR to finalise by 15th Feb with the secondary placement named.
If you give the LA an inch, they will take a mile. If they see parents don’t challenge their unlawful behaviour, LAs will continue to act unlawfully. (They sometimes still act unlawfully even if parents challenge unlawful behaviour, but LAs are more likely to act unlawfully when unchallenged.)