Does anyone know if there is currently a convenient way to choose which channel you want to be used to send a LN transaction, when you have several channels opened, without having to freeze all the other channels during the transaction please?
Most wallet software will choose the cheapest path, which is usually the shortest one. What do you want to accomplish? I don't find it reasonable to want your transaction to be charged higher. I could think of a privacy-related reason, but even that is invalid, especially when you receive, because you reveal your public key in BOL11 invoice.
No it's not a matter of privacy or of datas shown in the BOLT11 invoice. I don't want to accomplish anything special actually, I just want to be able to do that because I have different channels using different trampoline nodes, and I want to be able to decide which trampoline node I want to use because some of them seem to work more efficiently than other. In addition I also want to do that to be able to manage the receiving/sending capacity of my different channels. If I need to increase the receiving capacity of one channel, I want to be able to select it to send my next payment, same thing for a channel with a low sending capacity.