Shamim's Plugins

By default title and message max length is 100 and 5000.
Also your code seems correct to change that. Can you check if you have any more code which change this value?

I sent your modified custom plugin in your email, Did you received that?
You can reply to that email if require.

As we cannot send to both at the same time, so showing both option also is not available.
User can send message to any user, or click ” Message to administrator” which will show administrators name, from where they can send to administrator.

I do not understand your screenshots, can you make it in english?

You can send announcement to any role(s). You can go to front-end (from where you send message) and click “New Announcement”.

Groups are for sending message only. You can create group from role. Please see https://www.shamimsplugins.com/docs/front-end-pm-pro/getting-started-2/group-messaging/

Can you wait 1-2 weeks for this? I have already added the code so that it respect label and placeholder. In next version you will get it.

You are right, message_to elements has some other limitation. There are couple of other feature involved there (eg. multiple recipients, send to admin, send to group), so technically it is not one field but couple of field combined. Thats why it is not working there. But i will try to improve there in next version so that we can change placeholder, label there.

Google keys you are using is not for invisible captcha. Please create new keys from https://www.google.com/recaptcha/admin (select V2 Invisible when create keys) and add domain of this test website then add keys in settings page of this plugin.
Then let me know so that i can test.