Is there any easy tool to write raw transactions with a memo?

The idea is to build a complex transaction that have many outputs and some of them are MEMOs (using OP_RETURN) and spend one (or many) UTXOs.

A GUI tool would be awesome, but a CLI tool would also work. The important stuff is adding visibility for the fee for example, as a bad constructed transaction could be quite expensive.

In this this looking like question Electrum is mentioned, but it does not support adding a memo (as far as I understand).

It seems that there is a special syntax in Electrum to send an OP_RETURN memo on the GUI when sending to many:

script(OP_RETURN 5468697320697320612074657374),0
tb1qerzrlxcfu24davlur5sqmgzzgsal6wusda40er,0.00003

The syntax seems to not documented, but it is mentioned on some unit tests.

As far as I could test, the OP_RETURN should be a HEX encoded string. Here is the resulting transaction