First, I invite all of you to pray to St. Francis to intervene and end the persecution of the Franciscan Friars of the Immaculate.
Next, this is what St. Francis wrote about liturgical vestments.
A long time friend, the Great Roman Fabrizio™ once put together texts which give insight into what Francis was really about. He pulled quotes from the texts of Francis, most not translated into English elsewhere. He uses the exact words of St. Francis as found in the original Franciscan Sources and quoted in Latin (or Italian) original when available online. Otherwise, he transcribed them from the print edition. And online source for St. Francis’ own writings: OPUSCULA OMNIA SANCTI FRANCISCI ASSISIENSIS
The Poor Man of Assisi would not have been into clay pots and gunny sack vestments for Mass.
MYTH: Francis hated the “triumphalism” of the Roman Liturgy. He wanted Mass celebrated in barns, the Sacred Species held in shoe boxes or recycled bottles. And he couldn’t stand the “ritualism” of liturgical norms and devotional practices (and shall we mention his murky understanding of the doctrine on the Eucharist?):
Epistola ad custodes
To all the custodians of the Friars Minor to whom this letter shall come, Brother Francis, your servant and little one in the Lord God, greetings with new signs of heaven and earth which are great and most excellent before God and are considered least of all by many religious and by other men.
I beg you more than if it were a question of myself that, when it is becoming and you will deem it convenient, you humbly beseech the clerics to venerate above all the most holy Body and Blood of our Lord Jesus Christ and His Holy Name and written words which sanctify the body. They ought to hold the chalices, corporals, ornaments of the altar, and all that pertain to the Sacrifice as precious. And if the most holy Body of the Lord is left very poorly in any place, let It be moved by them to a precious place, according to the command of the Church and let It be carried with great veneration and administered to others with discretion. The Names also and written words of the Lord, In whatever unclean place they may be found, let them be collected, and then they must be put in a proper place. And in every time you preach, admonish the people about penance and that no one can be saved except he that receives the most holy Body and Blood of the Lord. And whenever It is being sacrificed by the priest on the altar and It is being carried to any place, let all the people give praise, honor, and glory to the Lord God Living and True on their bended knees. And let His praise be announced and preached to all peoples so that at every hour and when the bells are rung praise and thanks shall always be given to the Almighty God by all the people through the whole earth.
And whoever of my brothers custodians shall receive this writing, let them copy it and keep it with them and cause it to be copied for the brothers who have the office of preaching and the care of brothers, and let them preach all those things that are contained in this writing to the end: let them know they have the blessing of the Lord God and mine. And let these be for them true and holy obedience.