"daß er sich, was seine Wahrnehmung betraf, auf keine bestimmte Zahl festlegen mochte"

Question

This post is on the daß-clause in the following passage from Zwist unter Zauberern by Kurt Kusenberg.

In the story, two wizards, Parock and Schneidebein, are carrying on a feud. Parock receives a visit from three men looking remarkably alike posing as a customer, but actually they are Hem-Hem-Hem, spirits sent by Schneidebein. See picture at the bottom for more context.

Er [Parock] hielt sie [Hem-Hem-Hem] jedoch für Drillinge, und außerdem war er dermaßen bezecht, daß er sich, was seine Wahrnehmung betraf, auf keine bestimmte Zahl festlegen mochte.

QUESTION

1. I hope this question could be quickly got out of the way. Am I right to think keine. . . mochte here means be unwilling or hesitant, per this definition as found in Wiktionary?

   4 (auxiliary, in negation, with infinitive) to be hesitant to (do something)
     Ich mag sie nicht fragen. ― I am hesitant to ask her.

2. Here comes my real perplexity. According to WordReference festlegen is either a transitive verb meaning determine or a reflex verb meaning commit oneself. If so, the following bits seem to compete for the same accusative spot:

   sich
   was seine Wahrnehmung betraf

   Therefore I might suppose the clause can be expanded to the following?

   daß er sich auf keine bestimmte Zahl festlegen mochte und daß er, was seine Wahrnehmung betraf, auf keine bestimmte Zahl festlegen mochte.

   That is to say, he did not want to commit himself to a definite number and did not want to determine what struck his senses to be a definite number. Is this an ad hoc solution?

   Or maybe sich here is in the dative case, yielding the accusative spot to the was-clause? But the dictionary does not mention any such use of festlegen

   In short, how should I understand the clause syntactically? Above all, please confirm that both sich and was seine Wahrnehmung betraf are in the accusative, if that is the case, and how the two are related syntactically speaking.

BACKGROUND

Answer 1

I don't think sich and was seine Wahrnehmung betraf are competing for the the same accusative spot, as you put it. I think that was seine Wahrnehmung betraf is a parenthetical clause that relates to er.

In other words,

Was seine Wahrnehmung betraf, mochte er sich auf keine bestimmte Zahl festlegen.

Here's how I would translate the passage.

He thought however they were triplets. But he was so drunk anyway that, when it came to his perception of things, he couldn't be sure how many of them there were.

Answer 2

As most times, I'm more confused about your question than about the phrase you stumbled upon, and its translation to English. Maybe I'm too brisk?

The magic ‹pun intended› about this is the phrase was … betraf. This phrase restricts the item it follows. So Parock doesn't fully not commit himself, but only to the means of his cognitive abilities. Maybe he has magic knowledge?

Er [Parock] hielt sie [Hem-Hem-Hem] jedoch für Drillinge, und außerdem war er dermaßen bezecht, daß er sich, was seine Wahrnehmung betraf, auf keine bestimmte Zahl festlegen mochte.

He [Parock] deemed them [Hem-Hem-Hem] a triplet though, and above all he was well-oiled to such an extent he did, by the means of his cognition, not want to commit himself on a number.

→ He was drunk and saw one to ten Hems.