Just as an update: we are not ignoring you or anything, just talking over if/how we should do this :D

To be clear, openttdcoop.org used to host a SaaS variant of eints, where everyone could create their own project. One of them is yours.
OpenTTD never supplied eints as a SaaS; it hosts only our own projects (those in the https://github.com/OpenTTD namespace). It is also tightly coupled with our own infrastructure.
So there is no simple "transfer" as such; we have to recreate the SaaS, mostly meaning it has to become less coupled to our own infrastructure.

For example, one of those tightly coupled things: @DorpsGek needs push rights in the default branch of the GitHub repository for the project being translated (it cannot make Pull Requests currently). This might not be ideal for other projects, like yours.

So, we are looking into if and how we can offer eints as a SaaS via openttd.org. This will take some time to figure out.

So should I just use a service like https://gitlocalize.com/ or https://poeditor.com/ ?

That fully depends on you, of course. But that is not what I said. I am saying it is not a simple "transfer" as such, and we need some time to see how we want to create a SaaS out of our eints deployment. This won't be done overnight. My message was purely to inform you we have seen your request, and are looking into it.