Why deprecate experimental_standaloneMiddleware? - tRPC

I am reading https://trpc.io/docs/server/middlewares#experimental-standalone-middlewares, but it's still not clear to me why experimental_standaloneMiddleware was deprecated. It says we can use .concat() to use "standalone" middlewares. However, I don't see how they are related exactly? The example shows we can use a plugin. This would take in a new procedure to do concating of procedures. But this is not exactly what I want. In my code I have this: ```ts const todoAppInstalledMiddleware experimental_standaloneMiddleware<{ ctx: TProtectedProcedureContext; }>().create(async ({ ctx, next }) => { const foundPermission = await ctx.prisma.teamAppRole.findFirst({ where: { AppPermissions: { some: { id: "234234324-my-todo-app-id-here-yay", }, }, Team: { id: ctx.session.user.activeTeamId, }, Users: { some: { id: ctx.session.user.id, }, }, }, select: { id: true }, }); if (!foundPermission) throw new TRPCError({ code: "UNAUTHORIZED", message: `You don't have permission to do this. Contact an administrator if you believe it is an error.`, }); return next({ ctx }); }); ``` Doing this via concat() feels unnatural. I just want to define a middleware that I can use in multiple procedures where my session is not null (protected context). What is the recommended way of doing this?